猪CAST基因多态性与生物信息学分析

Polymorphism and bioinformatics analysis of pig CAST gene

本研究旨在检测巴克夏猪、霍寿黑猪及其杂交F_(1)代CAST基因多态性,并利用生物信息学分析碱基变异对mRNA二级结构以及CASTⅢ型蛋白的影响。结果表明,巴克夏猪、霍寿黑猪、巴克夏猪×霍寿黑猪都存在AA、AC和CC基因型,等位基因A的频率都高于等位基因C。该突变在3个猪群中均处于Hardy-Weinberg平衡状态(P>0.05),呈中度多态(0.25<PIC<0.5)。生物信息学预测结果显示,c.1980A>C使猪CAST基因mRNA序列的二级结构发生一定变化,并且最小自由能增大。p.Arg660Ser导致猪CASTⅢ型蛋白的部分理化性质略有改变,包括分子式、分子量、等电点、不稳定系数、总平均亲水性、正电荷(Arg和Lys)数等。p.Arg660Ser突变未改变猪CASTⅢ型蛋白的二级结构,突变前后都是无规卷曲和α-螺旋占的比例较高。p.Arg660Ser突变不位于猪CASTⅢ型蛋白的保守结构域上,但可导致催化相邻位p.663Ser磷酸化的蛋白激酶数减少。综上,c.1980A>C突变可能对猪CAST基因的转录效率和功能产生一定影响。

The aim of this study was to detect the CAST gene polymorphism of Berkshire pig,Huoshou black pig and their hybrid F_(1) generation,and to analyze the effect of base variation on the mRNA secondary structure and CAST typeⅢprotein by bioinformatics.The results showed that there were AA,AC and CC genotypes in Berkshire pig,Huoshou black pig and Berkshire×Huoshou black pig,and the frequency of allele A was higher than that of allele C.The mutation was in Hardy-Weinberg equilibrium in all three pig populations(P>0.05),and with moderate polymorphism(0.25<PIC<0.5).Bioinformatics prediction showed that c.1980A>C slightly changed the secondary structure of porcine CAST gene mRNA sequence,and increased the minimum free energy.The p.Arg660Ser mutation resulted in a slight change in some physicochemical properties of the porcine CAST typeⅢprotein,including molecular formula,molecular weight,isoelectric point,instability index,grand average of hydropathicity,positively charged residues(Arg and Lys)number.The secondary structure of porcine CAST typeⅢprotein was not changed by the missense mutation,and the proportion of random coil andα-helix were higher before and after mutation.The p.Arg660Ser mutation was not located in the conserved domain of the porcine CAST typeⅢprotein,but could lead to a decrease in the number of protein kinases that catalyzed the phosphorylation of adjacent p.663Ser.In summary,the c.1980A>C mutation might have a certain impact on the transcription efficiency and function of the pig CAST gene.