牛α-s1酪蛋白基因3＇端的克隆鉴定及序列分析

Cloning and Sequencing of 3’-flanking Region of Bovine α-s1 Casein Gene

本文用牛α-sl酪蛋白基因cDNA为探针,筛选了以EMBL3为载体构建的牛基因组文库2×10~5pfu,得到一个阳性克隆。分别以牛α-sl酪蛋白基因cDNA全长、终止符前后序列为探针鉴定了该克隆,制作了较为详细的限制酶谱,亚克隆了相应片段,并对含有终止符和poly A加成信号的有关亚克隆进行了序列分析,结果表明:该克隆含有牛α-sl酪蛋白基因终止符下游3.5kb及上游10.2kb片段,与现有的该基因的资料相比较,限制酶谱存在部分差异,DNA序列有多处点突变,并有少量缺失。点突变在内含子和外显子均有发生,这是限制酶图谱差异的原因。

A positive clone was isolated from a bovine genomic library in EMBL3 with the probe of α-S1 casein gene cDNA. The results from restriction endonucleases digestion, Southern bybridization with the probes of upstream and downstream from terminator of bovine α-S1 casein gene cDNA suggested that the clone contained 3.5kb downstream and 10.2kb upstream fragments from the terminator of α-s1 casein gene.Some divergence in restriction endonucleases sites, a few deletions and many point mutations were found in introns and exons when compared with those which had been published.