棉花叶绿体70S核糖体S7蛋白基因的克隆和序列分析

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同源性很高。应用ＰＣＲ技术，从棉花叶绿体基因组扩增并克隆了长度为１．０ｋｂ的叶绿体ＤＮＡ片段。该片段含有叶绿体核本小亚基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，并测定了该片段的含部核苷酸序列。结果表明，棉花叶绿体ｒｐａｓ７基因与烟草、不稻的相庆基因同源性高，分别为９７．９％和８９．５％，３非编码区的同源性分别为９６．３％

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

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%).