猪SGK家族基因的生物信息学分析及其在猪脂肪组织和细胞中的表达

doi:10.16431/j.cnki.1671-7236.2022.09.005

摘要/Abstract

摘要： 【目的】扩增猪血清和糖皮质激素诱导型激酶（SGK）家族基因并进行生物信息学分析，探索其在猪脂肪组织和细胞中的表达模式。【方法】以藏猪脂肪细胞cDNA为模板PCR扩增SGK家族基因，通过在线工具预测其编码蛋白的理化性质及亚细胞定位；用Mega X软件构建系统进化树；采集30日龄巴马猪心脏、肝脏、脾脏、肾脏、肺脏、背肌、腿肌、颈部脂肪、背部脂肪、腹股沟脂肪、肾周脂肪等组织及7日龄和4月龄猪腹股沟脂肪组织，通过实时荧光定量PCR检测SGK家族基因在猪不同部位组织中的表达；采集30日龄巴马猪腹股沟脂肪组织并分离基质血管成分（SVF）细胞，诱导SVF细胞向白色脂肪细胞分化，通过实时荧光定量PCR检测SGK家族基因及脂肪分化标记基因CCAAT增强子结合蛋白α（C/EBPα）、过氧化物酶体增殖物激活受体（PPARγ）在脂肪细胞中的表达。【结果】 SGK1、SGK2和SGK3基因CDS区序列长度分别为1 296、1 104和1 473 bp，分别编码431、367和490个氨基酸；SGK1和SGK2定位于细胞质，SGK3定位于细胞核，三者均为亲水性蛋白，3个蛋白均含有相同基序，保守性高；系统进化树结果表明，猪与牛的亲缘关系最近；SGK1和SGK3基因在心脏、肝脏、脾脏、肺脏、肾脏、多种肌肉及脂肪组织广泛表达，SGK2基因在颈部、背部、腹股沟、肾周脂肪组织中均有较高表达；SGK1和SGK2基因在7日龄猪脂肪组织中表达量极显著高于4月龄猪脂肪组织（P<0.01），SGK3基因在4月龄和7日龄的猪脂肪组织中表达量无显著差异（P>0.05），且SGK3基因的表达量低于SGK1和SGK2基因；与未分化脂肪细胞相比，在分化后的脂肪细胞中SGK1和SGK2基因的表达量极显著上调（P<0.01），且SGK1基因的表达量远高于SGK2基因，而SGK3基因的表达量无显著变化（P>0.05）。【结论】 SGK家族蛋白具有保守结构域，可能发挥着相似的功能，SGK1和SGK2可能参与调控猪脂肪细胞的分化过程，结果可为探究猪脂肪沉积的分子机制提供一定的理论基础。

关键词: 猪; SGK家族基因; 脂肪沉积; 表达分析

Abstract: 【Objective】 This study was aimed to amplify porcine serum and glucocorticoid-inducible kinase (SGK) family genes and analysis their bioinformatics, as well as to explore their expression patterns in porcine adipose tissues and adipocytes.【Method】 SGK family genes were amplified by PCR using the cDNA of Tibetan pig adipocytes.The physicochemical properties and subcellular localization of the encoded proteins were predicted by online tools.The phylogenetic tree was constructed by Mega X software.The tissues from heart, liver, spleen, kidney, lung, back muscle, leg muscle, cervical fat, backfat, inguinal fat, and perirenal fat of 30-day-old Bama pigs and the inguinal adipose tissues of 7-day-old and 4-month-old Bama pigs were collected.The expressions of SGK family genes in these tissues were detected by Real-time quantitative PCR.The 30-day-old porcine inguinal adipose tissues were collected and stromal vascular fraction (SVF) cells were isolated and differentiated into white adipocytes.The expressions of SGK family genes and adipocyte differentiation marker genes CCAAT/enhance binding protein alpha (C/EBPα) and peroxisome proliferator activated receptor gama (PPARγ) in adipocytes were detected by Real-time quantitative PCR.【Result】 The sequence length of the CDS regions of SGK1, SGK2 and SGK3 genes were 1 296, 1 104 and 1 473 bp, encoding 431, 367 and 490 amino acids, respectively.The SGK1 and SGK2 were localized in cytoplasm, and the SGK3 was localized in nucleus.All three SGK proteins were hydrophilic proteins with the same structural domains and conserved motifs of their encoded proteins.Phylogenetic tree results indicated that pigs were most closely related to cattles.SGK1 and SGK3 genes were widely expressed in heart, liver, spleen, lung, kidney, various muscles and adipose tissues.SGK2 gene was highly expressed in adipose tissues of the cervical fat, backfat, inguinal fat and perirenal fat.The expression of SGK1 and SGK2 genes were extremely significantly higher in adipose tissues of 7-day-old than 4-month-old pigs (P<0.01), and there was no significant difference in the expression of SGK3 gene between 4-month-old and 7-day-old pigs (P>0.05).The expression of SGK3 gene was lower than that of SGK1 and SGK2 genes.Compared with undifferentiated adipocytes, the expression of SGK1 and SGK2 genes were extremely significantly up-regulated in differentiated adipocytes (P<0.01), and the expression of SGK1 gene was higher than that of SGK2 gene, while the expression of SGK3 gene did not change significantly (P>0.05).【Conclusion】 SGK family proteins had conserved structural domains and might play similar functions.SGK1 and SGK2 might be involved in regulating the differentiation of porcine adipocytes, which laid a certain theoretical foundation for exploring the molecular mechanism of porcine fat deposition.

Key words: pigs; SGK family genes; fat deposition; expression analysis

中图分类号:

S829.9

陈川河, 刘嘉莉, 张立兰, 赵莹, 陶聪. 猪SGK家族基因的生物信息学分析及其在猪脂肪组织和细胞中的表达[J]. 中国畜牧兽医, 2022, 49(9): 3310-3320.

CHEN Chuanhe, LIU Jiali, ZHANG Lilan, ZHAO Ying, TAO Cong. Bioinformatics Analysis of Porcine SGK Family Genes and Their Expression in Porcine Adipose Tissues and Adipocytes[J]. China Animal Husbandry and Veterinary Medicine, 2022, 49(9): 3310-3320.

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