棉花叶绿体70S核糖体S7蛋白基因的克隆和序列分析

Cloning and Sequencing of the Gene for Cotton Chloroplast 70 S Ribosome S7 Protein

叶绿体基因组具有高度保守性,来源于不同植物的叶绿体基因的同源性很高。应用PCR技术,从棉花叶绿体基因组中扩增并克隆了长度为1.okb的叶绿体DNA片段。该片段含有叶绿体核糖体小亚基S7蛋白基因rps7。采用限制性内切酶消化连接的策略构建亚克隆,并测定了该片段的全部核苷酸序列。结果表明,棉花叶绿体rps7基因与烟草、水稻的相应基因同源性很高,分别为97.9％和89.5％,3’非编码区的同源性分别为96.3％和83.9％。本文首次报道了棉花叶绿体rps7基因的序列,并讨论了它的功能及保守性。

Chloroplast genome is highly conserved genetic system. Most of the genes in chloroplast genome from different plants have high homology. A 1. 0 kbp fragment was PCR amplified and cloned from cotton chloroplast genome. The fragment was subcloned and its complete nucleotide sequence was analysed. This fragment contains the gene encoding 70 S ribosome S7 subunit: rps 7. Through the analysis of the homology between cotton rps 7 and corresponding genes of tobacco and rice, the results showed high homology in both coding sequence(97.9% and 89. 5% nucleotide identical with tobacco and rice respectively) and 3'-untranslated region (96.3% and 83.9%).