【摘要】 牦牛(Bos mutus)是高原地区十分重要的种质资源。为研究牦牛血小板源性生长因子D (plateletderived growth factor D, PDGFD)基因的结构及功能，并探究其在牦牛不同年龄的7个组织中的表达情况，本研究以36月龄大通牦牛的皮下脂肪组织cDNA为模板克隆牦牛PDGFD基因的CDS序列，利用基因序列进行生物信息学分析及蛋白理化性质预测，q PCR检测PDGFD在大通牦牛胚胎期150 d与36月龄成年时期2个年龄段7个组织(心,肝,脾,肺,肾,背最长肌,皮下脂肪)中的相对表达量。结果表明，大通牦牛PDGFD的CDS区全长为1 095 bp，共编码氨基酸364个，同野牦牛PDGFD基因的亲缘关系最近(99.8%)，与猪(Sus scrofa)最远(91.2%)；牦牛PDGFD蛋白预测为稳定的亲水性分泌蛋白，无跨膜结构域，存在1个CUB结构域(116 aa)及1个PDGF结构域(93 aa);PDGFD蛋白高级结构由无规则卷曲(48.21%)、α-螺旋(25.62%)、延伸链(21.49%)和β-转角(4.68%)相互连接而成，主要与同为血小板源性生长因子、血管内皮生长因子相关蛋白相互作用。qPCR结果显示，牦牛2个发育阶段的7个组织中均有PDGFD基因的表达，在对比2个时期的PDGFD基因组织表达规律后发现，心脏中的基因表达维持在较高水平，脂肪组织中的基因表达量变化最大，随着牦牛生长极显著升高(P<0.001)。推测PDGFD基因与牦牛心脏发育有着密切关系，在生长发育过程中影响脂肪的沉积。本研究为PFGFD基因在牦牛脂肪沉积的调控机制的研究提供理论依据，可以作为牦牛的遗传育种的参考。更多还原

【Abstract】 Yak(Bos mutus) is an important genetic resource to the plateau region.To study the structure and function of the platelet-derived growth factor D(PDGFD) gene in yaks,and explore the PDGFD gene expression in different tissues at 2 age stages,this study cloned the complete PDGFD gene CDS sequence by using subcutaneous adipose tissue c DNA of 36-month-old Datong yak as the template.Biological software was used for analyzing the PDGFD gene nucleotide sequence and physical and chemical properties of protein.The relative expression of PDGFD in 7 tissues(heart,liver,spleen,lungs,kidney,longissimus muscle and adipose tissue) of embryonic and 36-months old yak was carried out by qPCR.The results showed that the CDS region of PDGFD gene was 1 095bp and encoded 364 amino acids.The most closely genetic relationship of Datong yak was the B.mutus(99.8%),and the most distant was the Sus scrofa(91.2%).The protein analysis of PDGFD showed that PDGFD contains 1 CUB domain of 116 aa,1 PDGF domain of 93 aa,and no transmembrane structure.PDGFD was predicted to be a stably hydrophilic secretory protein.The PDGFD protein advanced structure was consisted of random coil(48.21%),α-helix(25.62%),extended chain(21.49%),and β-turn(4.68%).In addition,PDGFD mainly interacted with platelet-derived growth factor protein and vascular endothelial growth factor protein.qPCR results showed that PDGFD mRNA was expressed in each tissue at 2stages.By comparing the 2 periods,PDGFD gene expression was maintained at a high level in the heart.Meanwhile,the expression in adipose tissue changed the most.The mRNA expression level of PDGFD extremely significantly increased in adipose tissue with the growth and development of yaks(P<0.001).The result showed that PDGFD may be closely related to yak’s heart,and affected adipose growth and development.This study offers a theoretical foundation for the regulation mechanism of yak fat deposition and provides references for the genetic breeding of yaks.更多还原