摘要
【目的】为了阐明大额牛和牦牛胃型LYZ c基因的多态性及其对消化功能的适应。【方法】采用PCR产物直接测序技术,对35头大额牛和33头牦牛样品胃型LYZ c基因完整编码区序列进行了变异检测,并结合已发表的牛科物种同源序列进行了其对消化功能的适应性分析。【结果】在大额牛群体内共发现6个SNP位点,分别为c.196G>A、c.267T>C、c.270C>T、c.396C>T、c.423C>T和c.438C>G。在牦牛群体内共发现10个SNP位点,其中6个与大额牛共享,非共享的SNP位点分别为c.336G>C、c.348T>G、c.351T>C和c.375A>C。SNP196和SNP348为异义替换,引起p.G66S和p.H116Q氨基酸替换,但它们对大额牛和牦牛LYZ c的功能没有影响。在大额牛LYZ c基因中,共定义6种单倍型,确定了2种LYZ c蛋白变异体(Gayal 1和Gayal 2);而在牦牛LYZ c基因中,共定义12种单倍型,确定了3种LYZ c变异体(Yak 1～Yak 3);变异体Gayal 1与Yak 3、Gayal 2与Yak 1相同,而变异体Yak 2为牦牛独有。大额牛、牦牛和普通牛胃型LYZ c变异体之间在氨基酸组成、理化特性与结构上基本一致,但大额牛和牦牛变异体LYZ c等电点比普通牛S3型LYZ c更低。【结论】大额牛和牦牛胃型LYZ c蛋白可能更适合胃中的酸性环境,具有分解胃中微生物的功能。
[Purpose]To clarify the genetic polymorphisms of gayal and yak gastric LYZ c gene and their adaptive evolution to digestion in the acid environment of stomach.[Methods]The variations in the complete coding region of gastric LYZ c gene were detected in 35 gayal and 33 yak samples by adopting the technique of PCR product direct sequencing in this study.Combined with published homologous sequences of some bovine species,the adaptive analysis of digestive function was further conducted by the methods of comparative genomics and bioinformatics.[Results]A total of 6 SNP sites were found in gayal,namely c.196G>A,c.267T>C,c.270C>T,c.396C>T,c.423C>T and c.438C>G,respectively.And 10 SNP sites were found in yak.Except 6 of which were shared with gayal,others viz.c.336G>C,c.348T>G,c.351T>C and c.375A>C were only found for yak.The SNP sites found in gayal were all shared with that of yak.The SNP196 and SNP328 were non-synonymous substitution,which result in p.G66S and p.H116Q amino acid changes.These two substitutions were presumed to have no effect on the function of stomach LYZ c.Based on the variations in gayal and yak gastric LYZ c gene,6 haplotypes were defined in gayal from which 2 protein variants were identified in gayal,namly Gayal 1 and Gayal 2.And 12 haplotypes were defined in yak from which 3 protein variants were identified in yak,namly Yak 1?Yak 3.Among them,variant Gayal 1 and Yak 3,Gayal 2 and Yak 1 were identical,and Yak 3 is unique to yak.The amino acid compositions,physiochemical properties and structures of the gayal,yak and cattle variants are basically the same.The above characteristics of gayal and yak gastric LYZ c are very similar to those of cattle,but the isoelectric points of gayal and yak gastric LYZ c are lower than that of cattle S3.[Conclusion]The results of this study indicate that gayal and yak gastric LYZ c is more suitable for the acid environment of the stomach,and it has the function of breaking down the microbes in the stomach.
作者
范新阳
张自芳
邱立华
钱林东
刘丽仙
张永云
苗永旺
FAN Xinyang;ZHANG Zifang;QIU Lihua;QIAN Lindong;LIU Lixian;ZHANG Yongyun;MIAO Yongwang(College of Animal Science and Technology,Yunnan Agricultural University,Kunming 650201,China;Institute of Animal Husbandry,Yunnan Vocational and Technical College of Agriculture,Kunming 650212,China;Teaching Demonstration Center of the Basic Experiments of Agricultural Majors,Yunnan Agricultural University,Kunming 650201,China)
出处
《云南农业大学学报（自然科学版）》
CSCD
北大核心
2018年第5期858-866,共9页
Journal of Yunnan Agricultural University:Natural Science
基金
国家自然科学基金项目(31460582
31760659)
云南省应用基础研究重点项目(2014FA032
2007C0003Z)
