China Animal Husbandry and Veterinary Medicine ›› 2019, Vol. 46 ›› Issue (9): 2676-2682.doi: 10.16431/j.cnki.1671-7236.2019.09.022

• Genetics and Breeding • Previous Articles     Next Articles

A Review of Some Factors Related to Embryo Implantation in Pigs

FU Yanfeng, FANG Xiaomin, LI Bixia, ZHAO Weimin, WANG Xuemin, CHEN Zhe, REN Shouwen   

  1. Jiangsu Germplasm Resources Protection and Utilization Platform, Key Laboratory of Crop and Livestock Integrated Farming, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
  • Received:2019-01-04 Online:2019-09-20 Published:2019-09-21

Abstract: Litter size is a significant economic trait in pig industry,and embryo implantation plays an important role in the litter size of pigs.Regulation of embryo implantation involves many biological processes,in which there are many substances (implantation factors) play functions.In this study,the authors summarized the relevant researches on progesterone,progesterone receptor,estradiol,estrogen receptor α (ESR1) and erythropoietin-producing hepatocellular receptor-ligand (Eph-ephrin) system,and the paper is focused on the spatial and temporal expression,function,mutation and regulation of these factors during porcine embryo implantation.Among these implantation factors,progesterone and its receptor play an important role in the whole process of embryo implantation.Progesterone secreted by the corpus luteum combines with the progesterone receptors in the tissues of endometrial epithelium,glandular epithelium,stroma and muscle in the pregnant sows,and the combination stimulates cells of these tissues to secrete a variety of implantation factors,which are further involved in the embryo implantation process.Estradiol is one of the most abundant and active estrogens and it is mainly secreted by ovarian granulosa cells,and ESR1 is the main receptor of estradiol in uterus.Combination of estradiol and ESR1 can make the sow estrus.In addition,blastocyst in the free state also secretes estradiol,which is a signal that is allowed to be recognized by endometrium of the sow.Eph-ephrin system has an extensive function,including its role in regulation of embryo implantation in human,mouse and pigs.EphA1,ephrin A1 and EphA4 genes of Eph-ephrin system have significantly higher expression in pregnant pigs during embryo implantation than that of non-pregnant pigs,and expression of these genes in endometrial attachment sites are significantly higher than that of inter-attachment sites.Besides,inhibition of ephrin A1 could reduce the migration and adhesion ability of endometrial epithelial cells.These implantation factors play important roles in porcine embryo implantation activities.In-depth researches on these factors will help to clarify the regulation mechanism of embryo attachment and further reveal the mechanism of high litter size in pigs.

Key words: pigs; embryo implantation; progesterone; estrogen; Eph-ephrin

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