摘要
用BLAST法比较了蓝藻和叶绿体中编码光合系统蛋白的基因碱基序列的同源性 ,其中蓝藻来自集胞藻6 80 3和念珠藻 712 0 ,叶绿体来自地钱、烟草、水稻、裸藻、黑松、玉米、紫菜、拟南芥等。以集胞藻 6 80 3的碱基序列为基准 (10 0 % ) ,与其他物种进行同源性比较。在光系统Ⅰ基因中 ,psaC同源性最高 (90 14 % ) ,最低的是 psaJ(5 2 2 4 % )。光系统Ⅱ基因中 ,同源性最高的是 psbD基因 (83 71% ) ,最低的是 psbN(4 9 70 % )。ATP合成酶基因中 ,同源性最高的是atpB基因 (79 5 8% ) ,最低的是atpF(2 6 6 9% )。细胞色素b6/f复合物基因中 ,同源性最高的是 petB(81 6 6 % ) ,最低的是petA(5 5 2 7% )。这些数据可为叶绿体的起源和进化提供一些证据。
This study compared homology of base sequences in genes encoding photosynthetic system proteins of cyanobacteria (Synechocystics sp.PCC6803,Nostoc sp.PCC7120) with these of chloroplasts (from Marchantia Polymorpha,Nicotiana tobacum,Oryza sativ,Euglena gracilis,Pinus thunbergii,Zea mays,Odentella sinesis,Cyanophora paradoxa,Porphyra purpurea and Arabidopsis thaliana) by BLAST method.While the gene sequence of Synechocystics sp.PCC6803 was considered as the criterion (100%) the homology of others were compared with it.Among the genes for photosystem Ⅰ,psaC homology was the highest (90.14%) and the lowest was psaJ (52.24%).The highest ones were psbD (83.71%) for photosystemⅡ,atpB (79.58%) for ATP synthase and petB (81.66%) for cytochrome b_6/f complex.The lowest ones were psbN (49.70%) for photosystemⅡ,atpF (26.69%) for ATP synthase and petA (55.27%) for cytochrome b_6/f complex.Also,this paper discussed why the homology of gene sequences was the highest or the lowest.No report has been published and this bioinformatics research may provide some evidences for the origin and evolution of chloroplasts.
基金
海洋 8 63计划资助 (课题编号 :819 0 4 11)~~
关键词
光合系统基因
碱基同源性
BLAST法
蓝藻
叶绿体
genes for photosynthetic system
homology of base sequences
BLAST method
cyanobacteria
chloroplasts
