无角山羊间性综合征缺失片段的序列特征

Sequence Analysis of the Deletion Region in PIS Goats

一段长约11.7 kb的片段缺失导致山羊无角和间性突变,称为无角间性综合征（Polled Intersex Syndrome,PIS）。通过对该缺失片段（AF404302）内4个重复序列（1~3120 bp,3988~4565 bp,4989~7088 bp,7875~9135 bp）的结构分析,发现其右侧一段属于LINE-1家族的L1M3分支（7875~9135 bp）,另3段均属于RTE家族的BDDF分支。以缺失片段内两段逆转录酶结构域的全长蛋白序列为参考对NCBI网站牛基因组数据库进行tblastn,并与得到的56条共有序列构建进化树,以此树为基础推断PIS缺失区域大约形成于（22.5~30）百万年前,正好是牛科动物分化趋异的年代,结合其他证据认为该调控方式可能只存在于牛科动物中。该发现也为PIS区域作用机理和non-LTR的竞争学说提供了证据。

A 11.7 kb deletion region triggers intersexuality and polledness in goats,termed as Polled Intersex Syndrome（PIS）.Through the sequence analysis of four repeated sequences（1-3 120 bp,3 988-4 565 bp,4 989-7 088 bp,7 875-9 135 bp） in goat PIS deletion region（AF404302）,we found that the 7 875-9 135 bp segment belonged to L1M3 subfamily of LINE-1 and the others were members of BDDF subfamily of RTE.Depending on the results of tblastn program searching using the full-length protein sequences of RT domain in PIS region as query sequences against the bovine genome database,56 consensus sequences were constructed.Using the consensus sequences we deduced the formation time of PIS region at（22.5-30） million years,just the divergence time of Bovidae from Artiodactyla.Combined with other evidence,the PIS region might only exist in Bovidae,and another evidence of the role of PIS region and the non-LTR competition doctrine was provided in this paper.