中国荷斯坦牛ABCG2基因编码区多态性检测及生物信息学分析

目的：研究中国荷斯坦牛ABCG2基因编码区（CDS）多态性,并进行生物信息学分析。方法：以中国荷斯坦牛为材料,利用PCR-SSCP技术对ABCG2基因CDS多态性进行检测,然后预测蛋白质序列的改变,并用生物信息学软件对蛋白质序列突变前后的结构及性质进行分析。结果：在外显子9中存在一个A→G碱基突变,导致氨基酸由酪氨酸突变为半胱氨酸,将此突变命名为Y367C;在外显子14中存在一个G→A突变,导致氨基酸由精氨酸突变为谷氨酰胺,将此突变命名为R578Q。2个突变一个位于功能区与跨膜区之间,一个位于跨膜区。生物信息学分析发现,蛋白质二级结构增加了1个卷曲（C）和2个转角（T）,同时减少了3个β折叠（E）,且ABCG2蛋白的组成和一些性质也发生了改变。结论：检测到的2个单核苷酸多态性引起了ABCG2蛋白性质和二级结构的改变;为进一步研究ABCG2蛋白对产乳性状的影响奠定了基础。

Polymorphisms Detection and Bioinformatics Analysis of Coding Domain Sequence of ABCG2 Gene in Chinese Holstein

Objective： To detect the polymorphisms of ABCG2（ATP binding cassette, subfamily G, member 2） gene CDS （coding domain sequence） in Chinese Holstein, and then analysis the structure and characteristic change of ABCG2 protein by bioinformaties. Methods： The polymorphisms of ABCG2 gene CDS were identifieated by PCR-SSCP in Chinese Hol- stein. The change of ABCG2 protein was predicted, then the structure and characteristics around mutation change of ABCG2 protein sequences were analyzed by bioinformatics software. Results： A single nucleotide polymorphism（SNP） A/G in exon9 was capable of tyrosine367 to cysteine（Y367C） and another SNP G/A in exonl4 was capable of arginine5788 to glutarnine（R578Q） in the ABCG2 gene. The component and character of ABCG2 protein have changed, secondary structure increased a coil and a turn, and the same time decreased three sheets by bioinformatics analysis. Conclusion： The AGCG2 protein characteristic and second structure changed by arise of two SNPs, it＇s established a foundation for research the effect of ABCG2 protein to milk production traits.