鸡生长激素基因内含子4新等位基因的序列分析

Sequencing for the New Alleles of Chicken Growth Hormone Gene Intron 4

试验以粤黄鸡矮脚黄系等不同肉鸡、蛋鸡品种 (系 )作为试验材料 ,对新发现的生长激素基因内含子 4等位基因的PCR产物作纯化后测序 ,研究多态性产生的机理及碱基变异情况。结果发现cGH内含子 4长约 1170bp ,内含子 4的A、B、C、D等位基因长分别为 1170bp、116 4bp、116 8bp和 116 6bp ,它们之间存在不同程度的碱基差异 ,而第 5 80碱基的突变 (A→G)和第 6 88碱基的突变 (A→G)分别产生了MspⅠ酶切位点 ,是多态性形成的根本原因。“PCR产物双带”的形成是由于cGH基因内含子 4其中一条链上第 42 0～ 470位碱基全部缺失。不同等位基因间存在碱基缺失、插入和替换 ,测序结果与酶切后电泳结果相吻合。

Intron 4 polymorphisms of cGH in different Chinese native chicken breeds(lines)and other breeds were determined and the new alleles were sequenced in the present study.The results showed that intron 4 was 1031-1200 bp long and that alleles A?B?C?D was 1170 bp?1164 bp?1168 bp and 1166 bp long,of which some base pairs were different.The change of the 580th base pair(A→G)and the 688th base pair(A→G)produced two sites of restriction enzyme MspⅠ,which was the causes of polymorphisms of cGH gene intron 4.'Two-band PCR product'was produced by 51 bp fragments deleted in position 420～470 of one chain.The sequencing results were consistent with those the electrophoresis showed.