牦牛与其他物种ZFX/ZFY基因片段间的进化关系

Evolution Analysis of ZFX/ZFY Gene Fragments Between Yak and Other Species

利用PCR扩增、克隆和序列分析法对牦牛ZFX/ZFY基因第11外显子部分片段进行了研究,并同来自于NCBIGenBank中人、猩猩、普通牛等9个物种的ZFX/ZFY基因核苷酸及其氨基酸序列进行了进化分析.结果表明,牦牛ZFX、ZFY基因间核苷酸序列同源性为94.1%,显示同一物种同源基因ZFX/ZFY间存在变异;比较的10个物种间ZFX基因核苷酸序列同源性为87.7%、ZFY基因为81.7%,相应ZFX、ZFY氨基酸同源性分别为96.6%、91.0%,ZFY基因的变异性大于ZFX基因,显示X染色体与Y染色体可能是独立进化.

Partial sequence of exon 11 of yak ZFX and ZFY genes were studied using PCR amplification, cloning, and sequencing. The obtained nucleotide sequence and the deduced amino acid sequences were compared with those from human, cow, orangutan, buffalo, horse, pig, coyote, tiger and cat. The results showed that the homology of nucleotide sequences between yak ZFY and ZFX was 94.1%, indicating the presence of variation between the two homologous genes. For nucleotide sequences, the homologies of ZFX and ZFY between yak and other animals were 87.7% and 81.7%, respectively. Whereas for the corresponding amino acid sequences, the homology of the two genes were 96.6% and 91.0%, respectively. The genetic variation of ZFY gene was larger than that of ZFX gene. These results suggest that the X chromosome and Y chromosome might evolve independently.