【Objective】 The purpose of this study was to investigate the effect of ribosomal protein L36A (RPL36A) gene on PK15 cells proliferation,and lay the foundation for the analysis of the physiological mechanism of the difference in growth rate between Mashen and Large White pigs.【Method】 siRNA and overexpression vectors of RPL36A gene were constructed and transfected into PK15 cells by liposome transfection method.The expression efficiency of RPL36A gene and the expression of genes (PCNA,Ki67,Cyclin B and CDK4) related cell proliferation in PK15 cells were detected by Real-time quantitative PCR and Western blotting.The scratch tests,CCK-8 and EdU methods were used to detect cell proliferation.【Result】 After overexpression of RPL36A gene in PK15 cells,the expression of PCNA,Ki67 and CDK4 genes mRNA were extremely significant increased (P＜0.01),the expression of Cyclin B gene mRNA was significantly increased (P＜0.05),and the expression of PCNA protein was significantly increased (P＜0.05).The number of PK15 cells at 48 h was extremely significantly higher than control group (P＜0.01),and the rate of proliferation was increased.The number of positive cells of PK15 cells were extremely significantly increased (P＜0.01).After interference of RPL36A gene in PK15 cells,the expression of PCNA and Cyclin B genes mRNA were extremely significant decreased (P＜0.01),the expression of Ki67 and CDK4 genes mRNA were significantly decreased (P＜0.05),and the expression of PCNA protein was significantly decreased (P＜0.05).The number of PK15 cells at 48 h was significantly lower than siNC group (P＜0.05),and the rate of proliferation was decreased.The number of positive cells was extremely significantly decreased (P＜0.01).【Conclusion】 After overexpression and interference of RPL36A gene in PK15 cells,the expression of PCNA,Ki67,Cyclin B and CDK4 genes,which were key genes for cell proliferation,as well as the number of PK15 cells and the number of positive cells,were significantly altered.The proliferation of PK15 cells was affected by RPL36A gene.

【Objective】 The purpose of this study was to investigate the effects of diacylglycerol acyltransferase 2 (DGAT2) on differentiation of bovine preadipocytes and its regulation of lipid metabolity-related signaling pathways.【Method】 The recombinant shuttle plasmid containing the target gene was constructed using the ADV1 shuttle plasmid,and then 293A cells were co-transfected with the recombinant shuttle plasmid and the skeleton plasmid pGP-Ad-Pac vector,and Adenovirus overexpressed vector Ad-DGAT2 was prepared.Bovine preadipocytes were infected with Ad-DGAT2 and Ad-NC (negative control group).96 h after differentiation induced by oleic acid,lipid droplet formation was observed by Oil red O staining,and the contents of triglyceride (TAG) and adiponectin (ADP) were detected.The expression of genes related to lipogenesis was detected by Real-time quantitative PCR.Finally,transcriptome sequencing was performed to screen differentially expressed genes,and GO functional annotation and KEGG pathway enrichment analysis were performed.【Result】 Overexpression of DGAT2 gene significantly increased the number of lipid droplets and the contents of TAG and ADP (P<0.05).Meanwhile,overexpression of DGAT2 could significantly up-regulate mRNA expression of DGAT1,glycerol phosphate acyltransferase 4 (GPAT4) and acylglycerol phosphate acyltransferase 4 (AGPAT4) in phosphoglycerol pathway and peroxisome roliferatoractivated receptor gamma (PPARγ),perilipin 2(PLIN2),CCAAT/enhancer binding protein α (C/EBPα) and stearoyl-COA desaturase (SCD) in lipid metabolism pathway (P＜0.05).Transcriptome sequencing results showed that a total of 110 differentially expressed genes were screened from preadipocytes infected with Ad-DGAT2 compared with Ad-NC group,among which 64 genes were up-regulated and 46 genes were down-regulated.KEGG pathway enrichment analysis showed that differentially expressed genes were mainly concentrated in the PPAR signaling pathway,glycerol phospholipid metabolism,fatty acid biosynthesis and AMPK signaling pathway.【Conclusion】 Overexpression of DGAT2 gene could promote lipid droplet formation,TAG accumulation and the expression of related adipogenic genes in Yanbian bovine adipocytes.Transcriptional sequencing screened out differentially expressed genes related to fat metabolism.The results indicated that DGAT2 gene played an important regulatory role in the differentiation of precursor adipocytes,which provided an important theoretical basis for molecular breeding of Yanbian bovine.

【Objective】 The purpose of this study was to construct expression system of Fowl adenovirus (FAdV) serotype 4 and 8b tandem truncated Fiber2-Fiber protein in Pichia pastoris,and explore appropriate expression conditions.【Method】 Using the previously constructed recombinant plasmid pCold-Fiber2-Fiber as the template,the Fiber2-Fiber fragments were amplified by PCR and the pPICZαA vector was connected.The positive recombinant plasmid by restriction digestion and sequencing was electrically transferred into Pichia pastoris GS115.After screening by MD plate and different concentrations of Zeocin resistance,the positive strains were identified by PCR amplification and sequencing.The positive strains were induced by methanol for 72 h,and the protein supernatant was collected for SDS-PAGE and liquid chromatography tandem mass spectrometry (LC-MS/MS) identification.Single factor variable test was used to optimize different expression conditions including pH (5.0,6.0,7.0 and 8.0),methanol concentration(0.5%,1.0%,1.5% and 2.0%) and time (24,48,72 and 96 h),and identified by SDS-PAGE.The reactogenicity of the recombinant protein was verified by indirect ELISA and Western blotting.【Result】 The recombinant plasmid pPICZαA-Fiber2-Fiber was successfully constructed.SDS-PAGE was performed on the supernatant expressed for 72 h and a specific band about 70 ku was found,which was identified as the target protein by LC-MS/MS.The optimum induction conditions of tandem truncated Fiber2-Fiber protein were pH 6.0,1% methanol and induction time 72 h.The results of indirect ELISA and Western blotting showed that the protein could specifically bind to the positive serum of FAdV-4 and FAdV-8b.【Conclusion】 The tandem truncated Fiber2-Fiber protein could be stably expressed in Pichia pastoris and had good reactivity,which laid a foundation for the development of FAdV bivalent subunit vaccine.

【Objective】 This study was aimed to investigate the quality of Calotropis gigantea and Pennisetum sinese silage with different mixed ratio,and provide a theoretical basis for the preparation of high-quality mixed silage and the development of new feed resources.【Method】 The proportions of Calotropis gigantea and Pennisetum sinese were 1∶0,2∶1,1∶1,1∶2 and 0∶1 (1C0P,2C1P,1C1P,1C2P and 0C1P groups),respectively.After 60 days ensilaging,the sensory score,nutrient components,fermentation qualities and cardiac glycosides contents in different groups were measured to identify the optimum mixed ratio of two plants.【Result】 The sensory evaluation of 1C1P,1C2P and 0C1P groups were better than that of 1C0P and 2C1P groups,which could reach the excellent grade.Different mixed proportions had significant effects on the nutritional components of mixed silage (P＜0.05).The content of lactic acid in 1C1P group were significantly higher than those in other groups (P＜0.05),and the content of butyric acid was not detected.Compared with before ensilaging,the contents of cardiac glycosides in 1C0P,2C1P,1C1P and 1C2P groups decreased by 4.87%,6.59%,11.49% and 9.52%,respectively.【Conclusion】 The mixed silage showed a significant effect on improving the quality of Calotropis gigantea silage,and played a degrading effect role on the content of cardiac glycoside.The best silage effect was obtained when the ratio of Calotropis gigantea and Pennisetum sinese was 1∶1.

【Objective】 This study was conducted to evaluate the effects of hydrolysable and condensed tannins on growth performance,body composition,digestive enzyme activities,serum biochemistry and antioxidant indexes of Litopenaeus vannamei.【Method】 A total of 800 shrimp (initial body weight was 1.04 g±0.02 g) were randomly divided into 5 groups with 4 replicates per group and 40 shrimp per replicate.Five diets including CON (control),HT0.1 (adding 0.1% hydrolysable tannins),HT0.2 (adding 0.2% hydrolysable tannins),CT0.1 (adding 0.1% condensed tannins) and CT0.2 (adding 0.2% condensed tannins) were formulated.The experiment lasted for 56 d.At the end of the experiment,the weight,quantity,and feed intake of shrimp per tank were counted to calculate the growth performance.Shrimp were randomly selected from each tank to determine the body compositions.Blood was collected from the cardiocoelom of shrimp to separate serum for determination of serum biochemical and antioxidant indexes.Hepatopancreas of shrimp were separated to determine the antioxidant indicators.Intestine of shrimp was separated for determination of the intestinal digestive enzyme activity.【Result】 Compared with CON,the final body weight (FBW),feed intake (FI),weight gain rate (WGR) and specific growth rate (SGR) in HT0.1 were significantly increased (P＜0.05),the FI in CT0.1 was significantly decreased (P＜0.05),and the FBW,FI,WGR and SGR in CT0.2 were significantly decreased (P＜0.05).The intestinal trypsin and lipase activities of shrimp in CT0.1 and CT0.2 were significantly decreased (P＜0.05).Compared with CON,HT0.2,CT0.1 and CT0.2 had higher (P＜0.05) serum alanine transaminase and aspartate aminotransferase activities,HT0.1 and HT0.2 had higher (P＜0.05) total antioxidant capacity (T-AOC),HT0.1 had higher (P＜0.05) but CT0.2 had lower (P＜0.05) serum catalase (CAT) activities,the serum malondialdehyde (MDA) level of shrimp in HT0.1,HT0.2,CT0.1 and CT0.2 were decreased (P＜0.05).Compared with CON,the hepatic T-AOC of shrimp in CT0.1 was increased (P＜0.05),the hepatic superoxide dismutase activity of shrimp in HT0.1,HT0.2,CT0.1 and CT0.2 were increased (P＜0.05),the hepatic CAT activity of shrimp in HT0.1 and CT0.1 were increased (P＜0.05),and the hepatic MDA level of shrimp in HT0.2 was decreased (P＜0.05).【Conclusion】 Taking the growth,digestion and antioxidation of Litopenaeus vannamei as the comprehensive evaluation indexes,the effects of supplementation of hydrolysable tannins was better than that of condensed tannins,and the appropriate ratio of dietary hydrolysable tannins was 0.1%.

【Objective】 The objective of this study was to compare the differences in the determination of amino acid contents of feeds using two amino acid analyzers (Biochrom 30⁺,Hitachi L-8900),which was expected to provide a reference for the additivity analysis of amino acid contents of feed measured by different amino acid analyzers.【Method】 A paired experimental design was adapted to compare the differences between two amino acid analyzers for the determination of amino acid contents of energy feeds (corn,brown rice,wheat,barley and paddy) and protein feeds (soybean meal,cottonseed meal,rapeseed meal,corn gluten meal and casein). Meanwhile the additivity of amino acids contents in corn-soybean meal diet were compared when the amino acid were determined with two amino acid analyzers. 【Result】 The contents of 7 amino acids (Lys,Val,Ile,His,Ser,Glu and Ala) in the energy feeds determined by Biochrom 30⁺ were less than those by Hitachi L-8900 (P＜0.05), but the contents of two amino acids (Glu,Cys) in protein feeds determined by Biochrom 30⁺ were higher than those by Hitachi L-8900 (P＜0.05). However,the relative bias of amino acid contents determined by those two amino acid analyzers was less than 3.0％. The differences of amino acid contents of energy feeds determined by two amino acid analyzers were greater than that of protein feeds. The ratios of values for energy feeds and protein feeds determined by Biochrom 30⁺ and Hitachi L-8900 ranged from 94.3％ to 105.0％,and 96.6％ to 102.4％,respectively. The determined values of amino acid content of corn-soybean meal diet by Biochrom 30⁺ and Hitachi L-8900 were 91.4％ to 107.8％ and 99.0％ to 104.3％ of the calculated values,respectively. The relative bias less than 4.0％ was observed between determined and calculated 11(determined by Biochrom 30^＋) and 14(determined by Hitachi L-8900) amino acid contents in corn-soybean meal diet. 【Conclusion】The amino acid contents of energy and protein feed had satisfactory consistency determined by two amino acid analyzers when samples were pretreated with the same condition. Additionally,the additivity of amino acid contents determined by Hitachi L-8900 was greater than that by Biochrom 30^＋.

【Objective】 This experiment was conducted to study the effect of overfeeding on growth and development,biochemical indexes,and meat quality of breast muscle in Pekin ducks.【Method】 One hundred and twenty 35-day-old Pekin ducks with similar body weights (2 529 g±40 g) were randomly divided into 2 groups (normal feeding group and overfeeding group) with 6 replicates per group and 10 ducks per replicate.The test period was 7 days,each duck in normal feeding group was fed 260 g/d on day 1-7,while each duck in overfeeding group was fed 260 g/d on day 1,300 g/d on day 2,and 420 g/d on day 3-7.At 42 days of age,2 ducks per replicate with 5 mL blood collected from the wing vein after 12 h fasting and then were slaughtered.The dressing,breast muscle and leg muscle were weighed,and percentage of dressing,breast muscle rate and leg muscle rate were calculated.The plasma and breast muscle biochemical indexes,meat quality and fatty acids in breast muscle were determined.【Result】 ① Compared with the normal feeding group,average body weight,average daily gain,dressing weight,percentage of dressing,breast muscle weight of Pekin ducks in the overfeeding group were significantly increased (P＜0.05),leg muscle weight and percentage of leg muscle were significantly decreased (P＜0.05).Feed/gain and breast muscle percentage had no significant differences between the two groups (P＞0.05).② Compared with the normal feeding group,plasma alanine aminotransferase (ALT) activity and alanine aminotransferase/aspartate aminotransferase (ALT/AST) in the overfeeding group were significantly increased (P＜0.05),and aspartate aminotransferase (AST) activity was significantly decreased (P＜0.05).Breast muscle water content,crude protein content,and malate dehydrogenase (MDH) activity were significantly reduced (P＜0.05),and intermuscular fat and triglyceride (TG) contents were significantly improved (P＜0.05).③ Compared with the normal feeding group,lightness (L^*),yellow ness (b^*),and cooking losses of breast muscle in the overfeeding group were significantly increased (P＜0.05).④ Compared with the normal feeding group,the contents of C22∶5 n-6 and polyunsaturated fatty acid/saturated fatty acid (PUFA/SFA) of breast muscle in the overfeeding group were significantly decreased (P＜0.05),while the contents of C14∶0,C16∶1 n-7,C18∶1 n-9,C20∶2 n-6,C20∶3 n-6,C22∶0,fatty acid (FA),unsaturated fatty acid (UFA),and monounsaturated fatty acid (MUFA) of breast muscle in the overfeeding group were significantly increased (P＜0.05).【Conclusion】 Overfeeding promoted the growth and development of Pekin ducks,enhanced the fat metabolism,increased the contents of intermuscular fat,total fatty acid,and unsaturated fatty acid in the breast muscle,decreased water and crude protein contents in the breast muscle,and the breast muscle meat cooking loss was higher in the overfeeding group.

Tannin is a kind of natural phenolic compound,which is mainly manifested as anti-inflammatory,antibacterial,antioxidant,antiviral and other biological activities.However,the significant differences in molecular composition and structure of tannin extracted from different plants have led to distinct roles for different sources of tannin in production farming.According to their structures,tannins are mainly divided into hydrolyzed tannin and condensed tannin.It has been shown that condensed tannin is commonly used as feed additives for ruminant livestock to improve rumen energy metabolism and increase feed utilization,while hydrolyzed tannin is mostly used as natural animal growth promoters and more widely used in pig and poultry farming.However,when applied in practice,the use of different concentrations of tannin has diverse effects.Therefore,to make full use of tannin resources in livestock farming,it is necessary to consider the source of tannin extract,the dose of tannin and the target of use.The authors present a review about the characteristics of different sources of tannins,and explain the potential reasons for the improvement of growth performance in different livestock by hydrolyzed tannins from Rhus chinensis Mill,chestnut(Castanea sativa Mill) and tara(Caesalpinia spinosa),and the possible mechanisms for the alteration of nitrogen metabolic pathways in ruminants by condensed tannins from Schinopsis spp.and Caragana korshinskii.Meanwhile,the specific applications of different sources of tannins and their applicable doses are discussed in order to provide theoretical guidance for the practical application of tannins in livestock farming.

【Objective】 To explore the difference of effects of early weaning on intestinal immunity and microbial diversity in Wuzhishan and Landrace pigs.【Method】 Six 50-day-old Landrace pigs and six Wuzhishan pigs (weaned at 28-day-old) with good growth,development and nutritional status were selected to collect the tissues,contents and mucosa of each segment of the small intestine.Paraffin section (HE staining),16S rDNA V3-V4 gene high-throughput sequencing and Real-time PCR were used to compare the differences between the two breeds in intestinal morphology,intestinal flora and the relative mRNA expression of intestinal mucosal immune-related genes.【Result】 ① The jejunal villus height of Wuzhishan pigs was significantly lower than that of Landrace pigs (P＜0.05).②The intestinal microbial diversity of Landrace pigs was more abundant in duodenum and ileum than that of Wuzhishan pigs (P＜0.05).③At the phylum level,the abundance of Firmicutes in the jejunum and ileum of Wuzhishan pigs was significantly higher than that of Landrace pigs,but Proteobacteria showed a reverse expression trend (P＜0.05).At the genus level,the abundance of Lactobacillus in ileum of Wuzhishan pigs was significantly higher than that of Landrace pigs (P＜0.05).④The detection results of mucosal immune related gene expression showed that the mRNA expression levels of anti-inflammatory factor IL-10 and tight junction protein ZO1 in duodenum of Landrace pigs were significantly higher than those of Wuzhishan pigs (P＜0.05),while the mRNA expression levels of pro-inflammatory factor TNF-α in jejunum and ileum were significantly lower than those in Wuzhishan pigs (P＜0.05).【Conclusion】 Compared with Landrace pigs,Wuzhishan pigs had poor intestinal immune performance and microbial diversity after early weaning.The weaning age of Wuzhishan pigs could be appropriately extended to reduce the diarrhea rate and ensure the survival rate of weaned piglets.

【Objective】 This experiment was conducted to investigate the effects of dietary supplementation of Cyberlindnera jadinii on nutrient digestibility,nitrogen metabolism,serum biochemical indexes and composition of fecal fungal community in growing raccoon dogs.【Method】 Forty-five healthy male raccoon dog with similar body weight at (60±5) day of age were randomly assigned to three treatment groups,with 15 raccoon dogs per group.Raccoon dogs in control group (N group) were fed a basal diet,raccoon dogs in experiment groups were fed the basal diet supplemented with low (L group) and high doses (H group) of Cyberlindnera jadinii,2 and 10 mL (1×10⁹ CFU/mL) per animal every day,respectively.A 7-day pretest period preceded a formal test period of 30 days.Manure and rations samples were collected in the last 3 days of the trial period to determine the nutrient apparent digestibility.Blood was collected before the morning feeding and fresh manure was collected after the morning feeding at the end of the trial period to determine the serum biochemical and fecal fungi composition.【Result】 Compared with N group,①the digestibility of ether extract and crude protein of raccoon dogs in L group were significantly increased (P＜0.05).The nitrogen retention and net protein utilization of raccoon dogs in L and H groups were significantly increased (P＜0.05).The fecal nitrogen excretion of raccoon dogs in L group was significantly decreased (P＜0.05).②Serum aspartate aminotransferase activity(AST) and triglycerides(TG) levels of raccoon dogs in L and H groups were significantly increased (P＜0.05).③The Chao1 and ACE indices of fecal fungi of raccoon dogs in H group were significantly decreased (P＜0.05).The relative abundances of Aspergillus and Talaromyces in the feces of raccoon dogs in L and H groups were significantly decreased (P＜0.05).The relative abundance of Cladosporium in the feces of raccoon dogs in H group was significantly decreased (P＜0.05).【Conclusion】 Dietary supplementation of Cyberlindnera jadinii could improve nutrient digestibility,nitrogen metabolism and reduce the relative abundance of harmful fungi in the feces of raccoon dogs.2 mL (1×10⁹ CFU/mL) per animal every day might be the most suitable addition level under the experimental conditions.

The balance of intestinal flora is closely related to the health and growth of animals.As a green and safe functional feed additive,organic acid (OA) has the effects of bacteriostasis,promoting digestion and regulating flora balance.With the continuous development of feed industry,OA has been gradually transformed from feed acidification,anticorrosion and mildew prevention to preparation,animal growth enhancers and anti-resistant products,and has become a functional additive widely used in the animal husbandry industry.The author reviewed the formation and distribution of pig intestinal flora,the effects of OA on the composition and diversity of pig intestinal flora,the production of metabolites and intestinal immune response,and the mechanism of regulating pig intestinal flora was discussed in order to further reveal the interaction mechanism between OA and intestinal flora,and provide reference for promoting pig intestinal health and rational utilization of OA.

As an important economic animal,sheep is one of the sources of meat,milk and fur in human society.Growth traits,carcass traits,breeding traits,reproductive traits,disease resistance and cold resistance are important economic traits of production and genetic breeding in sheep,understanding the molecular genetic basis of these traits,determining the key functional genes and genetic markers are conducive to improve the accuracy of important economic trait selection,and accelerate the genetic improvement of economic traits in sheep.With the development of genome resequencing,transcriptome sequencing and methylation sequencing,as well as the maturity of genome-wide association analysis technologies,there were many reports on the association analysis of phenotypic traits and genotypes in sheep,and a series of candidate genes and genetic marker related to economic traits in sheep have been excavated.The author summarized the available genetic marker genes screened in recent years mainly from the perspectives of growth and development,reproduction,tail lipid deposition and wool production,and selected some star genes,such as myocyte enhancer factor 2B (MEF2B) and somatostatin receptor 1 (SSTR1) affected body weight in sheep.Vertebrae development associated gene (VRTN) was a major gene that determines the number of thoracic vertebrae.Fecundity booroola (FecB),bone morphogenetic protein 15 (BMP15) and follicle stimulating hormone receptor (FSHR) were related to the breeding characters of sheep.Platelet derived growth factor D (PDGFD) and BMP2 genes were strongly selected in Fat-tailed sheep,and played an important role in tail fat deposition.Signaling protein agouti (ASIP) and melanocortin 1 receptor (MC1R) were significantly associated with hair color in sheep.The mutation sites,base changes and mutation types of available genetic markers affecting economic traits in sheep were summarized in this paper,which provided ideas for the subsequent research on genetic breeding in sheep.

【Objective】 This study was aimed to obtain the transcriptome information of ovary tissues in young and old sika deer,and provide a basis for further study the potential mechanism of ovarian aging in sika deer.【Method】 The ovaries of 4 years young sika deer and 10 years old sika deer were used as test samples.The samples were processed with paraffin sectioning,hematoxylin-eosin staining and follicle counting.RNA was extracted from the ovarian samples using the Trizol method,and a transcriptome library was constructed.The Illumina HiSeq^TM 2000 sequencing platform was used to sequence,the sequencing results were analyzed for differentially expressed genes,GO function,KEGG pathway and protein interaction network analysis.Selected differentially expressed genes were further analyzed using Real-time quantitative PCR.The expression of trimethylation of lysine 4 on histone H3 protein subunit (H3K4me3) protein in ovaries of young and old sika deer were detected by Western blotting analysis using RIPA lysis solution.【Result】 The histological analysis results showed that the number of ovarian follicles in old sika deer was significantly lower than that in young sika deer (P＜0.05),and the number of atresia follicles in old sika deer was extremely significantly higher than that of young sika deer (P＜0.01).Transcriptome analysis showed that there were 1 477 differentially expressed genes of ovaries between old and young sika deer,of which 503 genes were upregulated and 974 genes were downregulated.GO function and KEGG pathway enrichment analysis showed that the immune system process,transcription,DNA damage repair,inflammatory response,apoptosis and other biological events were related to ovarian aging.Real-time quantitative PCR results showed that there were 17 genes with significant or extremely significant expression of ovaries between old and young sika deer (P＜0.05 or P＜0.01),indicating that RNA-Seq results were reliable.Western blotting analysis results showed that the expression of H3K4me3 protein in ovaries was significantly different between old and young sika deer (P＜0.05).【Conclusion】 The number of follicles in ovaries of young and old sika deer showed a significant difference.The PI3K-Akt signaling pathway had been identified to affect the efficiency of DNA damage repair and participate in ovarian aging of sika deer via RNA-Seq.The high expression of H3K4me3 in ovaries of old sika deer was related to transcription activation.

The breeding of reproductive performance in sows has increased litter size,but high mortality of piglets at 5 days postnatal and even before weaning is still a major problem in production.The maternal behaviors of sows have an important impact on the survival,growth and welfare of piglets,thus affecting the breeding benefits.Therefore,the study on sow maternal behavior is of great significance.The maternal behavior in sows mainly include prenatal nesting,postpartum lactation,rearing,litter care and so on.The maternal behavior in sows is regulated by the interaction of nerves and hormones,and is also influenced by genetic,environment and other factors.With the adjustment of breeding objectives and the importance of animal welfare,the maternal behavior in sows has been studied by more and more scholars.The author reviewed the domestic and foreign research progress on the mechanism and influencing factors of maternal behavior in sows,and prospected the future research direction,which providing a theoretical basis and research ideas for subsequent research of maternal behavior in sows.

【Objective】 In order to explore the protective effect of antifreeze protein Ⅲ (AFP Ⅲ) on mitochondria of vitrified mouse oocytes. 【Method】 Kunming female mice aged 5-8 weeks were used as test materials,the collected mouse oocytes at MⅡ stage were randomly divided into blank control group,frozen control group and AFP Ⅲ adding group (500 ng/mL AFP Ⅲ was added to frozen balance solution and frozen solution),Mito-Tracker green (MTG) was used to detect the distribution and content of mitochondria,JC-1 fluorescence staining was used to detect mitochondrial membrane potential,Lyso-Tracker red (LTR) was used to detect the co-localization of mitochondria and lysosomes,dichlorofluorescein diacetic acid (DCFH-DA) was used to detect the level of ROS,and ATP Assay Kit was used to detect the content of mitochondrial ATP.【Result】 Compared with the blank control group,the content of mitochondria in mouse oocytes were decreased significantly after vitrification,some mitochondria showed abnormal scattered distribution,the co-localization of mitochondria and lysosomes were increased,and the mitochondrial membrane potential was decreased significantly (P＜0.05).Compared with the frozen control group,the mitochondrial content of mouse oocytes in AFP Ⅲ group was significantly increased,the abnormal distribution of mitochondria and the co-localization of mitochondria lysosomes were reduced,and the mitochondrial membrane potential was significantly increased (P＜0.05).Compared with the blank control group,the ROS content of mouse oocytes was significantly increased and ATP content was significantly decreased after vitrification (P＜0.05). Compared with the frozen control group,the ROS content of AFP Ⅲ group was significantly decreased and ATP content was significantly increased (P＜0.05).【Conclusion】 AFP Ⅲ could improve the oxidative stress response of vitrified mouse oocytes and protect mitochondria of frozen and thawed oocytes.

【Objective】 This experiment was aimed to investigate the expression of signal recognition particle 68 (SRP68) gene of different tissues in Hu sheep at different months,and analyze the effect of its polymorphism on the growth traits in Hu sheep,in order to find the molecular markers significantly related to the growth traits in sheep.【Method】 The expression of SRP68 gene in heart,liver,spleen,lung,kidney and longissimus dorsi muscle of Hu sheep was detected by Real-time quantitative PCR,as well as in the longissimus dorsi muscle of Hu sheep at birth,45-day,4-month-old and 6-month-old.The polymorphism site of SRP68 gene was detected by Illumina OvineSNP 50 BeadChip in 3 024 Hu sheep.The association between polymorphism site of SRP68 gene and the growth traits of 1 974 Hu sheep was analyzed by SPSS 26.0 software.【Result】 SRP68 gene was expressed in different tissues of Hu sheep,and the expression of longissimus dorsi muscle and heart in Hu sheep at 45-day and 4-month-old were extremely significantly higher than that of other tissues (P＜0.01),and the expression of longissimus dorsi muscle at 6-month-old was extremely significantly higher than that of other tissues (P＜0.01).There was moderate polymorphism at rs421715384 G＞A of SRP68 gene in Hu sheep population (0.25＜PIC＜0.5).The birth weight and 2-month-old weight of AA and GG genotypes were significantly higher than that of GA genotype (P＜0.05).The 5-month-old body height of AA genotype was significantly higher than that of GA and GG genotypes (P＜0.05),and the 6-month-old body weight,tube circumference and chest width of GG genotype were significantly higher than that of AA genotype (P＜0.05).【Conclusion】 SRP68 gene was closely related to the muscle development of Hu sheep,and rs421715384 G＞A could be used as a potential molecular marker for growth traits in Hu sheep,which could provide a reference for molecular breeding in Hu sheep.

【Objective】 This study was conducted to investigate the effect of the structural variation (SV) in the pig-specific cytochrome P450 3A 29 (CYP3A29) gene 3'-UTR on its expression,and analyze the relationship between the SV and the formation of meat quality traits in Xiang pigs.【Method】 The repeated elements,miRNA,and RBPs binding sites in the SV of CYP3A29 gene 3'-UTR were predicted by UCSC,miRBase,PITA and RBPsuite softwares in Xiang pigs and Large White pigs.The SV site was genotyped by PCR,the genotype frequency,gene frequency and Hardy-Weinberg equilibrium were calculated.The mRNA expression of CYP3A29 gene was detected by Real-time quantitative PCR.The content of CYP3A29 protein and the level of androgen (T and DHT) in muscle were detected by ELISA.Pearson correlation analysis between the contents of T and DHT and different genotypes was performed by SPSS 17.0 software.【Result】 Bioinformatics analysis results showed that the SV length of CYP3A29 gene 3'-UTR was 303 bp,and there was a short interspersed element (SINE) with a length of 241 bp in this variation,belonging to Pre0_SStRNA family,located in Chr3:6 819 917―6 820 161,containing 33 miRNAs and 13 RBPs binding sites.The genotyping confirmed that the SV in Xiang pigs and Large White pigs showed rich polymorphism,which contained insertion (II),hybrid (ID) and deletion (DD).The frequency of D allele in Xiang pigs was higher than that in Large White pigs.The SV was in Hardy-Weinberg equilibrium in Xiang pigs (P＞0.05),but not in Large White pigs (P＜0.05).The results of Real-time quantitative PCR and ELISA showed that the mRNA expression and protein content of ID genotype of CYP3A29 gene in Xiang pigs were significantly higher than II and DD genotypes,respectively (P＜0.05).The correlation analysis results showed that the expression of CYP3A29 gene of different genotypes was significantly correlated with T concentration of muscle tissue in Xiang pigs (P＜0.05),but not correlated with DHT concentration (P＞0.05).The T concentration of ID genotype in Xiang pigs was significantly higher than that of DD and II genotypes (P＜0.05),and DHT concentration of DD genotype was significantly higher than that of ID and II genotypes (P＜0.05).【Conclusion】 The SV of 303 bp in CYP3A29 gene 3'-UTR was polymorphic in Xiang pigs,and the deletion D allele was the main one,that was the SV lacked the SINE element in Xiang pigs,which leaded to the up-regulation of CYP3A29 gene expression,thereby affecting the T concentration of muscle tissue in Xiang pigs.In summary,the SV of CYP3A29 gene 3'-UTR was correlated with the meat quality traits in Xiang pigs.

【Objective】 The aim of this study was to reveal the milk production traits,patterns and factors influencing the lactation period of Camelus bactrianus,analyze the differential growth traits and blood and camel milk physiological and biochemical indicators of high and low Camelus bactrianus,and provide basic research information for the selection and breeding of high-yielding camels.【Method】 This study took the lactating Camelus bactrianus in Junggar as the research object,milk production was monitored,lactation curves were plotted during lactation,and the milk production of different litters was analyzed.Body size,body weight,and physical and chemical parameters of blood and camel milk were measured and analyzed for differences and correlations between high-yielding and low-yielding Camelus bactrianus.【Result】 The milking period of Camelus bactrianus was about 10 lactation months,with high milk production in the first 3 lactation months,a continuous decrease in milk production in the 4th to 7th lactation months,a slight increase in milk production in the 7th to 9th lactation months,and a minimum in the 10th lactation month,which could be summarized into 4 types of lactation curves.The peak of milk production was usually between 2 and 6 litters and the optimal age was 6 to 15 years.The milk yield of the high-yielding camel group was extremely significantly higher than that of the low-yielding camel group (P＜0.01).The weight,blood urea nitrogen,and blood urea of the high-yielding group were significantly higher than those of the low-yielding camel group (P＜0.05),while the serum albumin and calcium levels of the high-yielding camel group were significantly lower than those of the low-yielding camel group (P＜0.05).The milk fat and milk protein of the high-yielding camel group were significantly lower than those of the low-yielding camel (P＜0.01).The results of correlation analysis showed a strong correlation between blood physiological and biochemical indicators and milk production traits.【Conclusion】 The preliminary study revealed the milk production performance of Camelus bactrianus was affected by many factors such as body,lactation stage and nutritional environment,and there was a correlation between body weight,blood and milk composition and milk production,which provided theoretical data for further improving the milk production performance of Camelus bactrianus and selection and breeding of high-yielding camels.

ADP ribosyl transferase 3(ART3) is an ADP-ribosyl transferases,which is highly associated with nonobstructive azoospermia and cancer.Generally,interference with the ART3 gene or inhibition of the protein encoded by the gene results in low sperm density,high malformation rate and the spermatogenic cells in the seminiferous tubules fall off.It shows that ART3 is indispensable in spermatogenesis,and it is necessary to further study its function.At present,the specific roles of ART3 in spermatogenesis is unclear yet and there is very little reports on it.The author reviewed the protein structures of ARTs family members and their roles in spermatogenesis,the results of ART3 protein structure prediction and its localization in testicular tissue,and also summarized the ART3 functions in the pathogenesis of triple negative breast cancer and melanoma and the regulatory pathways in which ART3 had been involved.The review might serve as a scientific reference to help in unveiling the functions of ART3 in spermatogenesis,which might provide insight into the improvement of semen quality and the solutions to male sterility.

【Objective】 Using single and twin Mongolian sheep as animal models,the mechanism of the main effect gene of double lambs containing type Ⅰ platelet-binding protein motif of disintegrin-like metalloproteinase (ADAMTS-1) was preliminarily explored to provide a theoretical basis for efficient breeding and related research in Mongolian sheep.【Method】 Twelve female Mongolian sheep with records of single and double births were selected,and use natural estrus methods to determine the estrus and interestrus periods of female Mongolian sheep through vaginal mucosal smears and male sheep crawling.The ovaries of Mongolian sheep during the stages of double lambing estrus (DE),double lambing dioestrum (DD),single lambing estrus (SE),and single lambing dioestrum (SD) were collected,and the morphological differences of ovarian antral follicles were observed using HE staining.Granulosa cells from the ovary of Mongolian sheep were cultured and the location of ADAMTS-1 expression was determined by immunofluorescence.The relative mRNA expression of ADAMTS-1,progesterone receptor (PGR),mitogen-activated protein kinase 4 (MAPK4),androgen receptor (AR),serine protease inhibitor 2 (SERPINE2) and multifunctional proteoglycan proteoglycan (Versican) were determined by Real-time quantitative PCR in different groups.And the relative protein expression of ADAMTS-1 precursor protein (pro-ADAMTS-1) and mature protein (MP-ADAMTS-1) in different groups were detected by Western blotting.【Result】 There were no apparent differences in the morphology of the luminal follicles within the ovarian tissue from single and twin Mongolian sheep,as determined by the results of HE staining,and ADAMTS-1 was detected on granulosa cells in the ovary of Mongolian sheep using immunofluorescence.The results of fluorescence PCR and Western blotting showed that the gene and protein of ADAMTS-1 in ovarian tissue of Mongolian sheep in DE group were significantly higher than those in the other three groups (P＜0.05),while there was no significant difference between SE and SD groups (P>0.05). The expression of AR and PGR genes in ovarian tissue of Mongolian sheep in SE group were the highest and significantly higher than those in the other 3 groups (P＜0.05),and that in DE group was also significantly higher than that in DD group (P＜0.05).Moreover,the expression of AR and PGR genes in ovary of single lambs at the same diestrus stage was significantly higher than in ovary of double lambs.The expression of MAPK4 gene in ovarian tissue of Mongolian sheep in SE group were the highest and significantly higher than that the other three groups (P＜0.05),while there was no significant difference among the other three groups (P＞0.05).The expression of Versican and SERPINE2 genes in ovarian tissue of Mongolian sheep in DD group were the highest and significantly higher than those in DE and SD groups (P＜0.05),these two factors in SE group were significantly higher than that in SD group (P＜0.05).【Conclusion】 ADAMTS-1 was stably expressed in granulosa cells of ovary in Mongolian sheep,and ADAMTS-1 had an important positive regulatory role on ovulation mechanism of double lamb trait in Mongolian sheep,while various other hormone receptors and intracellular key signaling genes were also closely related to follicle development and expulsion in ovary.

【Objective】 Investigating the inhibition of anti-Müllerian hormone (AMH) on follicular development and the molecular mechanism in Shan-ma ducks.【Method】 40 healthy 29-week-old Shan-ma ducks were randomly divided into 4 groups.AMH1,AMH2 and AMH3 groups were given 2,20 and 200 μg/d AMH for 21 d,respectively.And the control group was given saline.During the experiment,egg production was recorded daily.Samples were collected at the end of this experiment,the number of follicles were counted,and calculated the gonadosomatic index (GSI).Serum luteinizing hormone (LH),progesterone (P₄) and estradiol (E₂) levels,the gene expression levels of Follicle stimulating hormone receptor (FSHR),luteinizing hormone receptor (LHR),steroidogenic acute regulatory protein (StAR),3β-hydroxysteroid dehydrogenase (3β-HSD),estrogen synthase (CYP19A1),growth differentiation factor 9 (GDF9),bone morphogenetic protein 15 (BMP15) in graded follicles (F6),small yellow follicles (SYF) and large white follicles (LWF),and the protein levels of StAR and GDF9 in F6 and SYF were detected.【Result】 Compared with control group, the laying rate were significantly decreased in AMH2 and AMH3 groups (P＜0.05),and AMH3 group showed the most significant inhibition of egg production rate. The numbers of SYF and LWF were significantly increased in AMH1 and AMH2 groups (P＜0.05), while GSI and the numbers of LYF had no significant trend. Serum LH, P4 and E2 level were in dose-dependent reduction, and AMH3 group showed a more pronounced inhibition of these hormones. LH level was significantly decreased in AMH3 group (P＜0.05). Compared with control group, the expression of GDF9 gene in AMH2 group and BMP15 gene in AMH1 group were significantly increased in F6 (P＜0.05). In SYF, except for GDF9 gene in the AMH2 group, the expression of FSHR gene was significantly decreased, while the expression of GDF9 and BMP15 genes in each experiment group were significantly increased (P＜0.05). The GDF9 protein level in AMH3 group was significantly increased (P＜0.05). The expression of GDF9 and BMP15 genes in AMH2 and AMH3 groups were significantly increased in LWF (P＜0.05). The administration of exogenous AMH did not significantly affect the expression of CYP19A1,3β-HSD and StAR genes in F6 and LWF (P＞0.05). In SYF, CYP19A1,3β-HSD and StAR genes were observed in AMH1, AMH2, and AMH3 groups were significantly lower than those of control group (except for CYP19A1 gene in AMH2 group, P＜0.05). Compared with control group, the administration of exogenous AMH had no significant effect on the protein levels of StAR in F6 and SYF (P＞0.05).【Conclusion】 200 μg/d exogenous AMH could significantly inhibit follicular development,mainly by inhibiting the secretion of LH,P₄,and E₂,upregulating the expression of GDF9 and BMP15 in follicles,downregulating the expression of FSHR and LHR,as well as key factors affecting steroid hormone synthesis pathways.

【Objective】 The aim of this study was to explore the genetic variation and genetic diversity of Canine distemper virus in Huaihua district and clarify its genetic evolutionary relationship.【Method】 Thirty Canine distemper virus samples were collected from Huaihua district and H and F gene sequences were amplified by PCR.The H and F gene sequences were analyzed by DNAStar software.Clustal X and MegAlign software were used to analyze variation sites and genetic diversity.Clustal X and PhyML 3.0 software were used to analyze the genetic evolution of Canine distemper virus in Huaihua area by maximum likelihood method (ML),and the genetic evolution tree was constructed by FigTree v 1.3.1 software.【Result】 Thirty Canine distemper viruses in Huaihua were Asian-type Ⅰ,and the H and F gene sequences were 1 778 and 1 850 bp,respectively.The contents of AT were 56.8%-57.9% and 54.9%-56.1%,and the contents of GC were 42.2%-43.0% and 44.1%-44.9%,respectively.The intraspecific and interspecific differences of H gene ranged from 0 to 3.1% and from 51.36% to 60.15%.The intraspecific difference of F gene was 0-2.4%,and the interspecific difference was 39.60%-53.09%.Based on the genetic evolutionary tree constructed by H and F gene sequences,it was found that 30 Canine distemper viruses from Huaihua were all located in the same branch of the genetic evolutionary tree.【Conclusion】 Canine distemper viruses from Huaihua were closely related to each other although there was a certain degree of genetic variation and genetic diversity among them.In addition,the H and F gene sequences of Canine distemper virus showed little intraspecific difference but great interspecific difference,which was an important genetic marker for studying gene variation,genetic diversity and genetic evolution of Canine distemper virus.

Runs of homozygosity (ROH) is a long homozygosity segment in the genome.ROH of different lengths and individuals are associated with the genetic background of a common ancestor,and the farther of genetic relationship has the shorter ROH fragment.In the process of inbreeding,with the increase of the number of generations,the ROH inherited from the common ancestor of the offspring individuals will be constantly interrupted and rearranged.ROH is subject to a variety of factors such as population inbreeding,population bottleneck,genomic characteristics and artificial selection,etc.,which will leave various imprints on its genome.There is abundant genetic information in ROH fragments,which equip a new tool for studying sheep genome information.In recent years,with the development of high-throughput sequencing technology,researchers use genome ROH to assess inbreeding degrees and population diversity,infer population structure and history,screen and identify important economic trait genes,and carry out individual selection track selection signals.Therefore,the author summarized the generation principle,influencing factors,detection methods and the application of ROH in sheep genetic breeding,so as to accurately formulate the protection strategy of sheep germplasm resources and provide theoretical basis for the application of ROH in sheep genetic breeding.

【Objective】 The aim of this study was to explore the accuracy and stability of dairy cow mastitis risk assessment system in pastures in North and South of China in recent years,and observe whether the system could be stably applied to predict mastitis of Chinese Holstein dairy.【Method】 Based on Logistic regression model of dairy cow mastitis (cow mastitis logistic regression model,CMLM) by the author’s research group had built,large scale horizontal and vertical data validation was conducted in 6 Holstein dairy farms in Beijing,Henan and Zhejiang.The dairy herd improvement (DHI) information of a total of 56 985 lactating dairy cows in 5 Holstein dairy farms in Northern region (Beijing and Henan) and 1 Holstein dairy farm in Southern region (Zhejiang) was used as the validation data.The prediction ability of risk assessment system for dairy cow mastitis was tested.More than 270 thousand DHI measurement records of pastures in Northern China from 2016 to 2021 were used to test the validation effect of CMLM on large scale vertical data in different time periods.【Result】 CMLM had a good accuracy in the validation data of pastures in Beijing,with an average accuracy of 71.85%.CMLM had a great actual application performance in the validation data of pastures in Henan which was new,with an average accuracy of 78.67%.CMLM had a stable actual application performance in the validation data of small-scale pasture in Southern region for 180 months,with an average accuracy of 77.63%.CMLM also had high predictive power at different time stages.The predictive value of the model was concentrated 0.70-0.90.It could be considered that CMLM was good.【Conclusion】 The CMLM system had excellent performance in the application of Holstein dairy herds in South and North of China,and had a high predictive effect in the verification of large scale horizontal and vertical data,which had a good promotion and application value.

【Objective】 This study was aimed to determine the pathogenic bacteria of Tibetan pigs in Ganzi Tibetan Autonomous Prefecture of Sichuan province,explore the genetic relationship and drug resistance among the strains,and provide scientific basis for effective prevention and control.【Method】 A suspicious pathogenic bacteria was isolated from lung of dead pig.The isolated strains were identified and analyzed by bacterial isolation and culture,16S rRNA PCR amplification and sequencing,genetic evolution analysis,drug sensitivity test,drug resistance gene and 23S rRNA mutation site detection,biofilm test and pathogenicity test of mice,respectively.【Result】 The results of 16S rRNA PCR amplification and genetic evolution analysis showed that the nucleotide sequence similarity between this strain and Spanish strain CR-18,LG6-7g,AR-5A and GM5-1 was 100%,respectively,and it was clustered into a genetic branch with Moraxella suis,indicating that this pathogen was Moraxella pluranimalium,named KD-4.Morphological observation result showed that this strain was a Gram negative diplococcus of kidney type.The biofilm test determined that the bacteria could form biofilm,so that the bacteria still colonized in the body after the animal disease healed,and became the host of the pathogen for a long time.The results of drug sensitivity test showed that this strain was highly sensitive to the antibiotics Fudaxin and sulfaisoxazole;Moderately sensitive to spectinomycin hydrochloride and meropenem;Resistant to ampicillin,gentamicin,amoxicillin,cefotaxifur sodium,florfenicol,tetracycline and enrofloxacin.Among them,the minimum inhibitory concentration (MIC) of Fudaxin,sulfaisoxazole,spectinomycin hydrochloride and meropenem against this bacterium were 2,128,64 and 2 μg/mL,respectively.The results of drug resistance gene detection showed that ermF,ermB,tetB,tetD,bla_TEM and bla_CTX-M genes were not detected.23S rRNA sequence analysis results showed that there were 15 mutation sites such as A2982T and C3132T,which might be related to the multiple drug resistance of the isolated strain.The pathogenicity test of mice showed that the bacteria could cause a small amount of bleeding spots in lung of mice,and the spleen was obviously swollen,but it was not fatal,and it could recover health after tolerance.【Conclusion】 This study was the first report of Moraxella pluranimalium from Tibetan pigs in China,and the results of drug sensitivity test could provide reference basis for disease prevention and epidemiological investigation caused by this bacterium.

Canine parvovirus disease endangers the health of the dog,the traditional vaccine can’t effectively protect dogs from viruses,looking for a new vaccine is a hotspot of current research and attention.VP2 protein is the main protective antigenic protein of Canine parvovirus (CPV),which plays an important role in determining host range and invasion process.In addition,the VP2 protein contains several important B-cell epitopes in the N and ring domains that induce the production of effective neutralizing antibodies during CPV infection.Therefore,VP2 protein is considered as the first choice of candidate antigens in the development of CPV genomic subunit vaccines.Viral-like particles (VLPs) are similar to natural viruses,but they do not have the replication function of natural viruses to cause infection in the body.Therefore,in recent years,the assembly of VP2 proteins using different expression systems has been a focus in the study of the researchers.The author focuses on the analysis of the characteristics and conformation of CPV VP2 protein.Through the analysis of the characteristics,it is known that the main component of CPV capsid contains VP2,which not only has hemagglutination activity,but also is closely related to the host range and antigenicity of CPV.Therefore,active VP2 protein is extremely important in the development of CPV genetic engineering subunit vaccine.According to conformational analysis,it is found that the Flexible loop of CPV VP2 protein has greater flexibility,which may be the molecular basis for the continuous expansion of the host range of CPV infection.At the same time,the author discusses the preparation methods and advantages and disadvantages of VLPs vaccines,in order to provide favorable references and scientific basis for the research and preparation of CPV vaccines.

【Objective】 The aim of this study was to understand the prevalence of Chlamydia in pets in Hangzhou.【Method】 238 pet dog conjunctival samples,556 pet cat conjunctival samples,98 pet bird serum samples and 264 parrot serum samples from a flower and bird market in Hangzhou were tested for Chlamydia using PCR and indirect hemagglutination assay (IHA),and the positive samples were sequenced.SPSS 25.0 software was used to analyze whether the age and gender of animals had statistical significance for Chlamydia infection.The similarity and evolutionary relationship between the main virulence genes of the epidemic strains and the published reference sequences were analyzed by Clustal W and Mega 11.0 softwares.【Result】 The results showed that pet dogs and birds were less susceptible to Chlamydia infection in animal hospitals compared to pet cats,and 13 positive samples were detected for pet cats, with a positive rate of 2.34%.The infection rate (3.57%) was highest in young cats (＜1 year old) and slightly higher in male cats (2.70%) than in female cats (2.02%),all differences were not significant (P＞0.05).Sequencing analysis of 13 positive cat samples revealed that all were Chlamydia felis,with genetic similarity to Chlamydia felis Fe/C-56 ompA gene ranging from 99.2% to 99.7%.14 positive samples were detected in parrots from flower and bird markets,with a positive rate of 5.30%.The infection rate (9.78%) was highest among infected parrots in young birds (＜1 year old) and higher in females (6.25%) than in males (4.41%),all differences were not statistically significant (P＞0.05).The prevalence of infection in parrots from flower and bird markets (5.30%) was higher than that in birds from animal hospitals (0),and 14 positive samples from parrots were sequenced and analyzed and found to be Chlamydia psittaci,with genetic similarity to Chlamydia psittaci 6BC ompA gene ranging from 99.4% to 99.5%.【Conclusion】 In this study,the prevalence of Chlamydia in pets in Hangzhou was investigated for the first time,and the results showed that Chlamydia infection existed in pet cats and parrots in flower and bird markets in Hangzhou,posing a potential threat to human health.Therefore,the importance of Chlamydia infection in pets should be raised and appropriate feeding management measures should be taken to prevent and control Chlamydia infection and avoid human-animal co-infection.

【Objective】 In this study,Toll/interleukin-1 receptor (TIR) domain protein (Bs-TDCP) of Brucella suis was used as the object of study,and gene cloning,bioinformatics analysis and protein interaction were performed.This will lay the foundation for the subsequent development of effective Brucella vaccines suitable for animal or human.【Method】 The GenBank database was used to find the gene sequences of Drosophila melanogaster myeloid differentiation factor 88 (Dm-MyD88) and Homo sapiensMyD88 (Hs-MyD88),and sequence-specific primers were designed for gene sequence amplification.Based on the sequencing results of Brucella suis,the Bs-TDCP gene sequence of TIR domain protein was obtained.ExPASy,SWISS-MODEL,TMHMM,SMART and other online tools were used to analyze the physical and chemical properties,secondary and tertiary structures,transmembrane and functional domains of Bs-TDCP protein,and further study the protein cross-talk between Bs-TDCP proteins and MyD88 molecules, a key intracellular ligand of Toll-like receptors (TLRs) signaling pathway.【Result】 The open reading frame (ORF) of Bs-TDCP gene of the TIR domain protein of Brucella suis was 828 bp,encoding 275 amino acids,of which 12.7% was alanine.The molecular formula was C₁₃₄₅H₂₁₉₆N₃₉₀O₄₂₄S₆,the molecular weight of the protein was 35.85 ku,and the theoretical isoelectric point was 9.37.The instability index of Bs-TDCP was 50.44,which was an unstable hydrophobic protein.It did not contain transmembrane domains and signal peptide sequences (SPS),but it had a typical TIR domain.The secondary structure of Bs-TDCP protein was composed of alpha helix,extended strand,beta turn and random coil,the percentages were 77.45%,8.36%,2.91% and 11.27%,respectively.The affinity purification effect of recombinant protein Bs-TDCP (rBs-TDCP),recombinant protein Dm-MyD88 (rDm-MyD88),and recombinant protein Hs-MyD88 (rHs-MyD88) was good.The results of the protein binding assay in vitro showed a protein interaction between Bs-TDCP without His tag (rBs-TDCP^△) and MyD88 molecules.【Conclusion】 rBs-TDCP^△ had some protein interaction with rDm-MyD88 and rBs-MyD88 ligands,respectively.The results provided theoretical reference for the development of novel brucellosis vaccines for human use.

The research on disease resistance breeding of herbivores is shifting from traditional breeding to molecular level.The antibodies in the immune system of herbivores have a very unique structure and diversity generation mechanism,and the rich antibody library is an important basis for the formation of disease resistance of herbivores.Antibody is composed of immunoglobulin,which has heavy chain and light chain,and the structure and diversity mechanism of immunoglobulin are different among herbivores.Although the number of immunoglobulin genes in herbivores is limited,the diverse mechanisms in various forms contribute to the formation of rich antibody libraries,which further enhance the immune capacity of animals.At present,the case fatality rate of herbivores in farms is relatively high,and the improvement of their immune levels is urgent.Therefore,it is very important to study the structure and diversity mechanism of their immunoglobulin.The author introduces the basic structure and different types of immunoglobulin,and briefly describe the gene structure and expression diversity mechanism of immunoglobulin in four herbivores:Cattle,sheep,rabbit and camel,in order to provide relevant theoretical basis and research ideas for the breeding of disease resistance.

【Objective】 The aim of this study was to establish an indirect ELISA method for detecting SIgA antibodies against Eimeria tenella in chicken intestinal mucosa in order to evaluate the specific mucosal immune level of Eimeria tenella in chicken.【Method】 The EtMIC2 and SO7 genes of Eimeria tenella were cloned into the prokaryotic expression vector pET-28a(+),and the recombinant plasmid EtMIC2-SO7 was constructed.The recombinant plasmid was transformed into Escherichia coli Rosetta (DE3) competent cells,and the expression of recombinant protein was induced by IPTG and identified by SDS-PAGE and Western blotting.The EtMIC2-SO7 recombinant protein was purified by nickel column affinity chromatography,and the protein concentration was determined by Bradford method. Using purified recombinant protein as the coating antigen,the optimal working concentration for ELISA detection of antigen and mucosa was determined by matrix titration.The optimal incubation time,type of blocking solution,enzyme-linked secondary antibody,and working conditions of the developing solution were determined by single variable method.Referring to the negative and positive criteria of ELISA antibody detection kit,S/P≥0.4 was positive,and S/P＜0.4 was negative as the negative and positive criteria for mucosal samples.The repeatability,specificity and sensitivity of the ELISA detection method were verified,and the coincidence rate was compared with the detection results of Eimeria tenella whole protein coated ELISA plate.【Result】 SDS-PAGE and Western blotting results showed that EtMIC2-SO7 recombinant protein with the size of about 70 ku was obtained,which was consistent with the expected results.The optimal antigen coating concentration of ELISA assay was 2 μg/mL,the optimal dilution of mucosa to be tested was 1∶40,the optimal incubation time of mucosa to be tested was 2 h,the optimal sealing solution was 5% skim milk powder,the optimal dilution of enzyme-conjugate secondary antibody was 1∶100 000,the optimal reaction time was 1 h,and the optimal color development time was 15 min.The coefficients of variation in both intra-batch and inter-batch repeatability tests were less than 10%.No cross-reactivity with specific SIgA antibodies against Newcastle disease virus,Avian influenza virus and Infectious bursal disease virus.Two positive intestinal mucosal samples were randomly selected for sensitivity test.When the dilution concentration was 1∶80,the two samples were still judged to be positive,indicating that the detection method was sensitive.The EtMIC2-SO7 recombinant protein and Eimeria tenella total protein were coated with ELISA plates,and 18 intestinal mucosal samples were detected.The results showed that the coincidence rate of EtMIC2-SO7 recombinant protein coated with ELISA plate and Eimeria tenella total protein coated with ELISA plate was 88.9%(16/18).【Conclusion】 The recombinant EtMIC2-SO7 protein was successfully expressed and purified by the prokaryotic expression system,and was used as the ELISA coated antigen.The indirect ELISA detection method of SIgA antibody against Eimeria tenella was successfully established with good repeatability,strong specificity and high sensitivity,which provided a preliminary detection method for mucosal immune evaluation of coccidium vaccine.

【Objective】 The purpose of this study was to construct a recombinant Adenovirus expressing Rabbit gemorrhagic disease virus type 2(RHDV2) VP60 protein leaded by Kozak sequence,based on a replication-defective Human adenovirus type 5(Ad5) and provide a basis for the research of RHDV2 new vaccine.【Method】 The VP60 gene with Kozak sequence were modified,synthesized and cloned to recombinant Adenovirus shuttle plasmid,and transferred into Escherichia coli TOP10 competent cells to construct Adenovirus shuttle vector,and the recombinants were analyzed and identified by restriction enzyme and sequencing.The recombinant Adenovirus Ad5-RHDV2-VP60 was packaged by the site-directed homologous recombination of shuttle plasmid and Adenovirus backbone plasmid,based on HEK293 cells using the Ad Max system.Then,the expression was verified by infecting HEK293 cells,and the recombinant Adenovirus was identified by RT-PCR,Western blotting and indirect immunofluorescence assay (IFA),and the titer of the recombinant Adenovirus was determined by Reed-Muench method.【Result】 Shuttle plasmid digestion result showed two bands with sizes of 3 895 and 1 752 bp,and the sequencing alignment results showed that it shared more than 99% similarity to the corresponding sequences published on GenBank,and the result showed that the shuttle plasmid was successfully constructed.The result of RT-PCR showed the 515 bp specific band,and the Western blotting result showed that the recombinant Adenovirus expressed a 60 ku VP60 protein.IFA results showed that HEK293 cells infected with the recombinant Adenovirus produced green fluorescence,and the VP60 specific protein could express in the HEK293 cells.The results of virus titer determination showed that the TCID₅₀of the primary recombinant Adenovirus was 10^5.5/0.1 mL.【Conclusion】 This study constructed a recombinant Adenovirus containing RHDV2 VP60 gene,which could successfully express RHDV2 VP60 with good antigenicity,and this study also provided a virus model for further research and development of RHDV2 vaccine.

【Objective】 To understand the drug resistance and molecular typing characteristics of Salmonellain the chicken production chain of modern agricultural and animal husbandry food enterprises with the links of breeding,slaughtering,transportation and sales.【Method】 In this study,37 strains of Salmonella isolated from the continuous samples collected from the farms,slaughterhouses,transport vehicles and franchised stores of an agricultural and animal husbandry food enterprise in Northern Jiangsu from October 2020 to September 2021 were tested for 13 common antibiotics by paper diffusion method,11 drug resistance genes by PCR,and molecular typing by pulsed field gel electrophoresis (PFGE).【Result】 The 37 strains of Salmonella isolated were all resistant,the highest resistance rate to ampicillin was 67.57%,the resistance rate to doxycycline,gentamicin and tetracycline was more than 50%,and the lowest resistance rate to cefoxitin was 8.11%.The resistance rate of Salmonella isolated from all links to ampicillin was more than 50%.Along the chicken production chain,the resistance rate of ampicillin showed a downward trend,and the drug resistance rate of ceftazidime,ceftriaxone,ciprofloxacin and tetracycline also showed a downward trend.The antibiotic resistance rate of cefoxitin,trimethoprim,gentamicin,amikacin showed an upward trend.34 strains were resistant to three or more antibiotics,and the multidrug resistance rate was 94.59%.The multidrug resistance rate of Salmonella isolated in breeding,transportation and marketing was 100%.The number of drug-resistant strains of Salmonella isolated from the links of breeding was mostly concentrated in 7 or more antibiotics,and the drug resistance rate to 8 antibiotics was higher than that of other links.The detection rate of drug resistance gene bla_PSE was the highest,and its detection rate was 56.76%.The drug resistance gene tetC was not detected.PFGE classification had produced 26 different PFGE belt types,and there were 7 groups of belt types with 100% similarity.【Conclusion】 Salmonella isolated from the chicken production chain of a modern agricultural and animal husbandry food enterprise in Northern Jiangsu had high drug resistance and serious multidrug resistance,and the drug resistance in the breeding link was higher than that in other links.PFGE typing suggested that the drug resistant strains could spread along the "Breeding-slaughtering"route of the chicken production chain,and existed for a long time.Avoiding the production of drug resistant Salmonella in the breeding link was the key point to ensure the safe production of chicken products.

Aleutian mink disease (AMD) is an important infectious disease of mink caused by the Aleutian mink disease virus (AMDV).Further research on AMDV is of great significance for the prevention and control of the disease.The AMDV genome is about 4.8 kb in length and encodes two structural proteins and three non-structural proteins,which play important roles in virus replication,proliferation and host pathogenic process.The replication of AMDV is dependent on metabolically active cells,and in young mink,viral infection of alveolar type Ⅱ cells causes acute lethal pneumonia,while infection of macrophages causes chronic progressive disease such as hypergammaglobulinemia and immune complex-mediated glomerulonephritis in adult mink.In this paper,the pathogenesis of AMDV is described in terms of its receptor pathway of cell invasion,apoptosis induction pathway and viral replication.AMDV is widely prevalent worldwide,and the existing detection methods are mainly serological diagnostic methods and molecular biology diagnostic methods.At present,no safe and effective commercial vaccine against AMDV has been developed,and with the rapid development of biological technology,progress has been made in the development of the inactivated vaccine,DNA vaccine and subunit vaccine.New methods of antiviral such as screening of AMDV-tolerant mink,improving mink immunity and targeted aptamer technology provide new ideas for the prevention and control of AMD.This article summarizes the research progress of AMDV at home and abroad in recent years in terms of AMDV encoding protein function,viral cell tropism and replication,clinical manifestations and pathogenesis,diagnostic methods and control measures,aiming to provide a reference for the development of safe and effective vaccines and drugs for the prevention and control of AMDV.

【Objective】 The purpose of this study was to investigate the epidemiological characteristics and genetic variation of Pseudorabies virus (PRV) in swine in Henan Province.【Method】 gE antibody levels were detected by ELISA in 25 411 serum samples collected from 766 pig farms in Henan Province during 2020-2021.gE gene was amplified by PCR in 251 samples from 47 pig farms suspected of PRV-infected pigs,and the positive samples were inoculated with ST cells for virus isolation,gE gene sequencing and genetic evolution analysis.【Result】 The total positive rate of gE antibody in serum samples was 18.42%,which decreased from 20.32% in 2020 to 16.69% in 2021.The positive rate in pig farms was 50.26%.With the increase of pig farm size, the positive rate of farm and serum sample showed a downward trend. The farm and serum positive rate in commodity farm, slaughterhouse and pig breeding farm decreased successively. The positive rates of gE antibody in eastern, western, southern, northern and central Henan were 15.05%, 23.48%, 16.50%, 16.69% and 20.10%, respectively. The positive rates were the highest from January to March and the lowest from October to December.The positive rate of PRV in tissue samples was 15.14% (38/251).A total of 9 PRV isolates were isolated from PRV positive samples.Phylogenetic analysis based on the gE complete sequences indicated that all isolates belonged to Genotype Ⅱ and there were both classical strains and variant strains in pig herds.【Conclusion】 PRV classical strains and PRV variant strains still existed in pig farms in Henan province.The results provided reference for the prevention and control and purification of PRV in Henan province.

【Objective】 Based on the theory of hypoxia-inflammation-endothelial proliferation,the pathogenesis of lung in broilers with ascites syndrome was explored,and the preventive and therapeutic mechanism of compound traditional Chinese medicine was studied.【Method】One hundred and fifty 8-day-old healthy AA broilers were randomly divided into 5 groups and fed routinely in blank control group.The ascites syndrome model group was established by multi-factor method of low temperature,high energy feed and high sodium drinking water.On the basis of model group,2.0,1.0 and 0.5 g/kg of compound traditional Chinese medicine were added to the daily drinking water of high,medium and low dose groups according to their body weight,respectively.The changes of clinical symptoms and anatomy were observed,the white blood cell count was detected by automatic hematology analyzer,the expression of hypoxia-inducible factor-1α(HIF-1α),vascular cell adhesion molecule 1(VCAM1),Sprouty-related,EVH1 domain-containing protein 1(SPRED1) and phosphatidylinositol 3-kinase regulatory subunit 2(PIK3R2) genes and miRNA-126-3p in lung were detected by Real-time quantitative PCR,and the expression of VCAM1,SPRED1 and PIK3R2 proteins in lung was detected by ELISA.【Result】 Compared with blank control group,broilers in model group were apathetic,had an enlarged abdomen,and on necropsy,they were found to have a large number of ascites in the abdominal cavity,pulmonary and hepatomegaly congestion,and had pericardial effusion.The white blood cell counts of broilers in model group at the age of 25,35,45 and 55 days were extremely significantly increased (P＜0.01);The expression of HIF-1α gene in lung of broilers in model group at the age of 35 days was extremely significantly increased (P＜0.01);The gene and protein expression of VCAM1 in lung of broilers in model group at the age of 15,25,35 and 45 days were extremely significantly increased (P＜0.01).The expression of SPRED1 gene and PIK3R2 protein in lung of broilers in model group at the age of 15 days were extremely significantly decreased (P＜0.01).The gene and protein expression of SPRED1 and PIK3R2 in lung of broilers in model group at the age of 25,35 and 45 days were extremely significantly decreased (P＜0.01).The expression of miRNA-126-3p in lung of broilers in model group at the age of 35 days was extremely significantly increased (P＜0.01).Compared with model group,the above results of broilers in each dose group of compound traditional Chinese medicine were improved to various degrees,and among them,the changes of each index in high dose group of compound traditional Chinese medicine were the most obvious.【Conclusion】 Inflammation and proliferation abnormalities triggered by hypoxia in lung were involved in the development of ascites syndrome in broilers.Compound traditional Chinese medicine could effectively prevent and treat ascites syndrome in broilers,among which 2.0 g/mL compound traditional Chinese medicine had the best effect.The mechanism of action was closely related to the regulation of hypoxia,inflammation,and proliferation in lung.

It contains a large number of microorganisms in the intestines of mammals such as mice,pigs,cattle,sheep,humans,etc.,which are essential for intestinal homeostasis and host health.Intestinal microbial disorders can lead to intestinal inflammation,nervous system diseases,functional and metabolic disorders and other diseases,which cause serious harm to animal and human health.Different species and breeds exhibit unique gut microbial characteristics,and the homeostatic balance of these microorganisms is important for animal health.At this stage,the research has found that fecal microbiota transplantation (FMT) plays an important role in restoring intestinal microbial dysregulation and intervening or reconstructing the balance of mammalian intestinal microbiota,and FMT is gradually widely used in infectious and non-infectious diseases.With the development of FMT technology,there is a new direction for the research whether mammals treat intestinal diseases by regulating microorganisms or other diseases,and this technical means is gradually widely used in various research fields.Based on the application of FMT in existing research areas,this review summarized the research progress on FMT widely used in the intestine and its related to diseases,so as to establish a more standardized,efficient,safe and beneficial FMT system for mammals,and provide new references and ideas for FMT in improving mammalian production performance,breeding and disease prevention.

【Objective】 The aim of this study was to analyze and predict the potential active ingredients and targets of Lonicerae Japonicae Flos to alleviate oxidative stress in cattle and explore its possible mechanism of action.【Method】 The active ingredients of Lonicerae Japonicae Flos were collected using Traditional Chinese Medicine Database and Analysis Platform (TCMSP) and literature search,and the targets corresponding to the active ingredients were identified using TCMSP and SwissTargetPrediction databases,and oxidative stress in cattle-related genes were collected in the gene platform of the NCBI database.The STRING database and Cytoscape 3.8.2 software were used to construct and analyze the protein-protein interaction network of Lonicerae Japonicae Flos and oxidative stress in cattle.GO function and KEGG pathway enrichment analysis of the intersection targets were performed using the DAVID database.Molecular docking was performed by AutoDock software to verify the binding activity of key active ingredients to the core targets.【Result】 There were 37 active ingredients of Lonicerae Japonicae Flos,which were involved in 37 targets related to oxidative stress in cattle.Among them,quercetin,kaempferol,luteolin,rutin and chryseriol were the key active ingredients of Lonicerae Japonicae Flos to alleviate oxidative stress in cattle,and tumor necrosis factor (TNF),prostaglandin-endoperoxide synthase 2 (PTGS2),catenin beta-1 (CTNNB1),serum albumin (ALB),caspase 3 (CASP3),catalase (CAT) and tumor protein p53 (TP53) were the core targets to alleviate oxidative stress in cattle.GO functional enrichment and KEGG pathway analysis showed that the targets were involved in biological process, cell component and molecular function,and were involved in multiple metabolic pathways such as HIF-1 signaling pathway,peroxisome,and MAPK signaling pathway.Molecular docking confirmed that quercetin,kaempferol and luteolin,the key active ingredients of honeysuckle,have good binding activities to the common core targets TNF,PTGS2,CTNNB1,ALB,CASP3,CAT and TP53.【Conclusion】 The results of the study revealed the potential active ingredients of Lonicerae Japonicae Flos to alleviate oxidative stress in cattle were quercetin,kaempferol,luteolin,etc.,and the potential action targets were TNF,PTGS2,CTNNB1,etc.,providing theoretical references for the development and subsequent research of Lonicerae Japonicae Flos as a functional feed additive.

【Objective】 This study was constructed to establish a method for the determination of the mass concentration of dicyclanil and its metabolites 2,4,6-triamino-5-pyrimidinecarbonitrile in sheep tissue by ultra-high liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).【Method】 Sheep tissues (muscle,fat,liver and kidney) were pretreated.Acetonitrile and heptafluorobutyric acid aqueous solution were used as mobile phases,Acquity UPLC Beh C18 column was used for gradient elution.The flow rate was 0.15 mL/min,the column temperature was 30 ℃ and the injection volume was 5 μL.The data were collected by multi-reaction monitoring in positive ion scanning mode,and the concentrations of dicyclanil and its metabolites were determined by external standard method.The linear range,detection limit,quantitative limit,recovery rate,intra-assay and inter-assay precision,accuracy and stability of the method were investigated.【Result】 The established detection method had high sensitivity,the detection limit was 10 μg/kg,and the limit of quantitation was 20 μg/kg.The addition concentrations of dicyclanil and 2,4,6-triamino-5-pyrimidinecarbonitrile were in the range of 20 to 1 000 μg/kg,and the linear relationship between the standard curves was good,with correlation coefficients ≥0.99.The recoveries of dicyclanil and 2,4,6-triamino-5-pyrimidinecarbonitrile were 70% to 110% when they were added to the blank tissues at high,medium,low and limited quantification levels,and the coefficient of variation within and between batches was less than 15%.The stability of dicyclanil and 2,4,6-triamino-5-pyrimidinecarbonitrile in different tissues was good under the conditions of investigation.【Conclusion】 The established UPLC-MS/MS assay was specific,reproducible and sensitive,and could be used for pharmacokinetic and residual studies of dicyclanil emulsion in sheep tissues.

【Objective】 The purpose of this study was to screen and analyze the role of circRNA in canine mammary gland tumor (CMGT) resistance,and provide a new target for tumor diagnosis and treatment.【Method】 Taking CMGT cell CHMm as the research object,we firstly constructed CMGT tamoxifen (TAM) resistant cell lines by concentration gradient method and concentration maintenance method,then verified its resistance by CCK8,and finally screened differentially expressed circRNAs in drug-resistant cells by high-throughput sequencing technology.GO function and KEGG signaling pathway were used to analyze the biological processes in which it might be involved.【Result】 The results showed that after continuous TAM stimulation,the CHMm morphology changed into long spindle shape,and the half inhibitory concentration (IC₅₀) increased from 4.07 to 13.75 μmol/L,indicating that the drug-resistant cells showed stronger TAM resistance.Sequencing results showed that 46 circRNAs were differentially expressed in drug-resistant cells.GO function analysis involved the processes of tumor extracellular matrix,protein ubiquitination,cell adhesion and cell migration,and the major signaling pathways were Notch,Rap1,ErbB,FoxO and PI3K pathways.【Conclusion】 In this study,the tamoxifen-resistant cell line CHMm^TAM was successfully constructed in CMGT and the resistant cells showed stronger proliferation ability and TAM resistance.The differentially expressed circRNAs in parents and drug-resistant cells were screened in high throughput.It was also found that the generation of drug resistance might affect biological processes such as cell signal transduction,cell ubiquitination and cell metastasis through Notch,Rap1 and ErbB pathways,and ultimately participate in tumor drug resistance.

【Objective】 This study was aimed to establish a method for the identification and content determination of Shenjiang Zhili mixture,and to provide a basis for the quality standard of the preparation.【Method】 Thin-layer chromatography (TLC) was used to analyze the Sophora flavescens and Zingiberis Rhizoma for qualitative identification research,and high performance liquid chromatography (HPLC) method was utilized to determine the content of matrine and oxymatrine. 【Result】 TLC results showed that the spots of the test samples in the TLC of Sophora flavescens and Zingiberis Rhizoma were clear,and the corresponding reference substances showed consistent spots in the same position on the TLC plate,while the negative control samples did not show characteristic spots. HPLC results showed that matrine and oxymatrine had good chromatogram peaks. The linear range of matrine from 5 to 100 μg/mL (R²=0.9999) and oxymatrine from 5 to 100 μg/mL (R²=0.9999) were good. The relative standard deviation (RSD) value (n=6) of the instrument precision test was 1.56%,indicating that the precision of the instrument was good and could meet the requirements of the subsequent content determination.At 0,6,12,24,36 and 48 h after the preparation of the sample solution,the calculated RSD (n=6) was 2.25%,indicating that the total content of matrine and oxymatrine in the sample solution remained stable at room temperature for 48 h. Reproducibility test results RSD (n=6) was 2.47%,indicating good reproducibility of the sample preparation method. The average recovery of total matrine and oxymatrine was 99.17%,RSD (n=6) was 2.84%. 【Conclusion】 The results showed that the reproducibility of qualitative and quantitative analysis methods of Shenjiang Zhili mixture was good,the results were accurate and reliable,and it could be used to identify Sophora flavescens and Zingiberis Rhizoma in Shenjiang Zhili mixture and to determine matrine and oxymatrine content,so as to effectively control the quality of matrine.

Pathogenic Escherichia coli (E.coli) as a member of Enterobacteriaceae and one of the zoonotic pathogens,can cause human and animal infections through a variety of ways and cause different E.coli disease types under certain conditions.Due to the large number of serotypes and virulence factors,the severe trend of drug resistance,the existence of biofilm and other factors,the epidemic trend of colibacillosis is complex and the development of vaccines is difficult of pathogenic E.coli,which brings certain economic losses to the domestic and foreign livestock and poultry breeding industry.High-pathogenicity island (HPI) was first discovered in Yersinia,which was proved to be a genomic island necessary for its virulence phenotype.Due to the horizontal transfer mechanism of bacteria,the virulence island is widely detected in other Enterobacteriaceae.Among them,the HPI pathogenicity island was also detected in pathogenic E.coli such as enterohemorrhage E.coli (EHEC) and shiga toxin-producing E.coli (STEC),which was confirmed to affect the virulence of pathogenic E.coli,participate in the iron uptake of pathogenic E.coli and mediate the host immune response.In order to further understand the iron regulation mechanism,pathogenic characteristics,mediated cellular immune response and horizontal transfer pathway of HPI virulence island in pathogenic E.coli,this paper summarizes the structure of HPI virulence island,how to regulate Yersinia siderophore,the pathogenicity of HPI virulence island and its regulation of cellular immune response,and the horizontal transfer of HPI virulence island.It is expected to provide help for the pathogenic mechanism of E.coli and the prevention and control of E.coli disease.

【Objective】 This study was conducted to explore the effect of total flavonoids from Melastoma dodecandrum Lour.on lipid metabolism in rats with high fat diet induced nonalcoholic fatty liver disease (NAFLD).【Method】 Sixty SPF male rats were randomly divided into blank group,model group,orlistat group,high,medium and low dose of total flavonoids from Melastoma dodecandrum Lour.groups,with 10 rats in each group.The rats in blank group were fed a basal diet,and the other groups were fed a high fat diet.Orlistat group was given 60 mg/kg orlistat,while high,medium and low dose groups were given 750,500 and 330 mg/kg total flavonoids from Melastoma dodecandrum Lour.,respectively.The corresponding drugs were given by intragastric administration at the volume of 0.1 mL/10 g every day for 42 days.The blank and model group were given equal volume of distilled water.The general status of rats in each group was recorded,and fasting blood glucose (FBG),fasting insulin (FINS),the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the levels of adiponectin (ADP) and leptin (LEP) were detected after administration.Insulin sensitivity index (ISI) and insulin resistance index (HOMA-IR) were analyzed.The contents of triglyceride (TG) and total cholesterol (TC) in liver were detected.Oil red O staining was used to observe the pathological changes of liver.The mRNA and protein expressions of peroxidase proliferator-activated receptor γ (PPARγ),adiponectin receptor 2 (AdipoR2) and p38 in liver of rats in each group were detected by Real-time quantitative PCR and Western blotting,respectively.【Result】 Compared with blank group, the activities of ALT and AST and the levels of LEP, FINS, FBG and HOMA-IR of serum in model group were extremely significantly or significantly increased (P＜0.01 or P＜0.05), the levels of ADP and ISI were extremely significantly decreased (P＜0.01), and more fat was deposited in the liver. The NAFLD model of rat was successfully established. Compared with model group,the activities of ALT and AST in serum and the levels of LEP,FINS,FBG and HOMA-IR in orlistat and high dose of total flavonoids from Melastoma dodecandrum Lour.groups were significantly or extremely significantly decreased (P<0.05 or P<0.01),ADP and ISI levels were extremely significantly increased (P<0.01).The contents of TC and TG in liver of orlistat and high,medium and low dose of total flavonoids from Melastoma dodecandrum Lour.groups were extremely significantly or significantly decreased (P<0.01 or P<0.05),there was less fat deposition in liver,and the mRNA and protein levels of PPARγ,AdipoR2 and p38 were extremely significantly increased (P<0.01).【Conclusion】 Total flavonoids from Melastoma dodecandrum Lour.could significantly improve NAFLD in rats induced by high fat diet,and its mechanism might be related to its involvement in regulating glucolipid metabolism,improving insulin resistance,and regulating PPARγ/AdipoR2/p38 signaling pathway.