南阳牛mtDNA D-loop序列多态性分析

本文以3头南阳牛线粒体DNA D-loop区910bp的核苷酸序列进行了分析。结果发现，3头南阳牛D－loop区的核苷酸序列有3种单倍型。南阳牛1、2和3号D－loop区的平均核苷酸变异率分别为0.44%、4.84%和0.44%，其高变区的平均核苷酸变异率分别为0.81%、7.57%和0.00％。南阳牛1号的核苷酸变异类型只有转换一种式，南阳牛2号的核苷酸变异类型有转换、颠换、插入和缺失四种形式，南阳牛3号的核苷酸变异类型有转换和插入两种形式。在3头牛的核苷酸变异类型中，均以转换最常。说明南阳牛mtDNA D-loop区表现出丰富的核苷酸变异多态性。从线粒体D－loop区核苷酸序列的3种单倍型分析，提出南阳牛可能有两种不同的母系起源。

Analysis on Sequence Polymorphism of mtDNA D-loop Region in Nanyang Cattle

The mitochondrial DNA D loop region of Nanyang cattle was analyzed in this study. The results showed that there were three types of nucleotide haplotype of mtDNA D loop region in experimented Nanyang cattle. The average nucleotide mutational rates of the D loop region in Nanyang cattle No.1, No.2 and No.3 were 0.44%, 4.84% and 0.44%,respectively, and their average nucleotide mutational rate of hypervariable region was 0.81%, 7.57% and 0.00%,respectively. Only transition was found in mtDNA D loop region in Nanyang cattle No.1, transition and insertion were found in cattle No.3, and four types of nucleotide variation including transition, transversion, insertion and deletion were found in cattle No.2, of which the transition was frequent. Those indicated that rich nucleotide variational polymorphism of mtDNA D loop region existed in Nanyang cattle. After analyzing the bovine mtDNA D loop nucleotide haplotypes, it was possible that there were two maternal origins in Nanyang cattle population.