松辽黑猪IGF-Ⅰ基因5′调控区序列特征分析

Sequence Characterization of the 5′-Regulatory Region of the IGF-Ⅰ Gene in Songliao Black Pig

对松辽黑猪类胰岛素样生长因子-Ⅰ(IGF-Ⅰ)基因5′调控区进行了T-A克隆和序列测定,在分析序列结构特征的基础上与GenBank中野猪、大白猪、牛、山羊、绵羊进行了比较基因组学和系统进化研究。结果表明:松辽黑猪IGF-Ⅰ基因5′调控区存在C/EBPb、MATal、Oct-1、CF-1等多个潜在的转录因子结合位点,可能与IGF-Ⅰ的转录调控和起始以及特异表达有关。在该非编码序列中,重复序列所占比率为2.22%,不存在SINEs、LINEs、LTR类反转录元件和DNA转座子元件,而发现存在1个(CA)18微卫星位点。在松辽黑猪IGF-Ⅰ基因5′调控区,松辽黑猪与野猪、大白猪、牛、山羊、绵羊各物种间同源性大小分别为99.0%、98.8%、90.7%、91.6%、90.6%。MUPD法构建的分子系统进化树聚类结果表明,野猪与大白猪先聚为一类,再与松辽黑猪聚类形成一个大分支,而山羊和绵羊先聚成一类,再与牛聚类形成一个大分支,然后再与猪的一支汇合在一起。

The 5＇-Regulatory region sequence of the IGF- Ⅰ gene in Songliao black pig was cloned by T - A method. Characterization and comparison of this sequence with Sus scrofa, White landrance, cat- tle,goat and sheep were also conducted. Results showed that： the 5＇-Regulatory region contained many potential transcriptional factor binding sites such as those for C/EBPb, MATal, CF-1,and Oct-1, which might have an important effect on transcription activation and regulation as well as tissue-specific expres- sion. The rate of repetitive sequences was 2.22 % and no SINEs, LINEs, LTR anti-transcription ele- ments or DNA transposon elements were found, although one（CA）18 mierosatellite was found. In the 5＇ regulatory region, sequence homology between Songliao black pig and Sus scrofa, White landrance, cattle, goat and sheep was 99.0%, 98.8%, 90.7%, 91.6% and 90.6%, respectively. The molecular phylogenetic tree among these species, constructed by the MUPD method based on the sequences of 5＇ regulatory region of the IGF- Ⅰ gene, placed the Sus scrofa and White landrance on one branch and the Songliao black pig on the other. Goat and sheep were joined first, followed by the cattle.