小球藻psbA基因的克隆与序列分析

psbA基因编码光合系统II反应中心的D1蛋白,是叶绿体基因组中一个重要的光调控基因。对小球藻属4个种的6株小球藻psbA基因进行了PCR扩增和测序,并结合GenBank上已有的2条小球藻psbA基因序列,使用MEGA3.1软件对psbA序列进行了遗传距离值的计算和系统发育树的构建。结果显示8株小球藻psbA基因的遗传距离值为0.012~0.167。除了原始小球藻F-2和蛋白核小球藻820分别与蛋白核小球藻F-5、F-9及与普通小球藻Cvq关系极近之外,其他6株小球藻基本上按照种的划分进行聚类,该结果与用小球藻的ITS和rbcL序列分析的结果一致。

Cloning and Analyses of psbA Gene from Unicellular Green Alga Chlorella

The psbA gene coding for D1 protein in photosynthetic II reaction centre is one of the important light-regulated genes in the chloroplast genome.The psbA genes from 6 strains in genus Chlorella were amplified by PCR and sequenced.Combined with the other two psbA sequences in the GenBank database,the distances in 8 psbA sequences were calculated and phylogenetic tree was constructed using MEGA3.1 software.The results showed that the genetic distances in the 8 Chlorella strains ranged from 0.012 to 0.167.The 8 strains of Chlorella were basically clustered according to their species relationships except for C.protothecoides F-2 and C.pyrenoidosa 820,which showed very close relationship with C.pyrenoidosa F-5 and F-9 and with C.vulgaris Cvq,respectively.This results were consistent with those obtained from the ITS or rbcL sequences of Chlorella.