新民猪RYR1和MC4R基因的多态性检测分析

为了调查兰尼定1型受体(RYR1)基因和黑素皮质素受体4(MC4R)基因[其目前公认的数量性状基因座(QTN)]在新组建的民猪群体内的分布情况,试验采用PCR-RFLP的方法,对黑龙江省农业科学院畜牧研究所收集整理的23头民猪的RYR1基因和MC4R基因进行检测,并与其他已报道的猪种进行比较。结果表明:RYR1基因的N等位基因频率为86.96%,n等位基因频率为13.04%;MC4R的A等位基因频率为76.19%,G等位基因频率为23.81%,与其他猪种相比,n等位基因频率偏高。     

Analysis of a polymorphism in the DGAT1 gene in 14 cattle breeds through PCR-SSCP methods

The diacylglycerol O-acyltransferase (DGAT1) is a microsomal enzyme that catalyzes the final step of triglyceride synthesis. Recent work have evidenced a significant association between lysine at amino acid position 232 with elevated milk fat content, while an alanine at this position is associated with lowered milk fat content. The aim of the present work was to develop a simple and inexpensive PCR-SSCP assay in order to discriminate the CG/AA alleles in exon 8 of the DGAT1 gene. In addition, this method was used to analyze the polymorphism of the DGAT1 through PCR-SSCP methods in 14 populations of cattle from Argentine, Bolivia and Uruguay. The PCR primers were designed from GenBank reported sequences. In this study, we found three PCR-SSCP variants, which were denominated from "A" to "C". However, DNA sequencing analysis showed that "A" variant corresponded with the A allele, while both "B" and "C" observed pattern have the motif AA at positions 10,433-10,434 (K allele), being two alternative conformations of the same DNA sequence. Both variants were detected within each breed with the exception of Hereford, and the heterozygosity varied between 0.000 and 0.524. The gene frequency analysis evidenced significant differences among the studied breeds (F(ST) = 0.325, p = 0.000). European Bos taurus breeds, with the exception of Jersey breed, showed the lowest frequency of the K allele, while highest K allele frequencies were harboured by Bos indicus type cattle. In addition, unselected South American Creole cattle breeds and the synthetic Brangus breed had intermediate allele frequencies.     

猪ECH1基因部分序列的遗传变异分析

为了进一步研究烯脂酰辅酶A水解酶1(enoyl CoA hydratase,ECH1)基因的生物学功能,研究采用克隆测序结合PCR-RFLP的方法分析了民猪ECH1基因的部分DNA序列,并对其中的1个点突变进行了3个猪种内的基因型频率和基因频率计算。结果表明:研究所检测的ECH1基因序列与网上已有序列相比存在8个单核苷酸多态性(SNPs)位点,其中有2个造成酶切位点的改变;民猪和大白猪在PCR-RFLP-BamHⅠ位点的A、B基因频率均接近0.5,而长白猪B为优势等位基因。