cpcHID操纵子序列用于钝顶节旋藻品系分类与鉴定的研究

克隆并测定7株钝顶节旋藻品系的cpcHID操纵子序列,以及16SrRNA和16S-23SrRNA转录单元内间隔区(ITS)序列,进一步通过生物信息学和分子系统学等研究发现:(1)7株品系的cpcHID序列,以及16SrRNA和ITS序列具有很高的相似性。(2)基于7株品系cpcHID序列的GC含量绝对偏差平均值、碱基变异率和遗传距离系数普遍比基于16SrRNA和ITS序列的大。(3)基于cpcHID序列的分类结果与基于16SrRNA和ITS序列的十分相近。因此,cpcHID可作为节旋藻等蓝细菌分类与鉴定的一种新的分子标记,特别是以其丰富的信息量而在品系水平的分类鉴定中占有优势。

cpcHID operon as a new tool for classification and identification of Arthrospira platensis strains

Arthrospira is a photoautotrophic filamentous cyanobacterium belonging to the family Oscillatoriaceae, phylum Cyanophyta. Morphological criteria alone were inadequate for classification of Arthrospira. To develop new molecular markers, in this study, the cpcHID operon, 16S rRNA and 16S-23S rRNA internally transcribed spacer (ITS) of seven Arthrospira platensis strains, Sp-10, Sp-2, Sp-9, Sp-1, Sp-11, Sp-3 and Sp-5, were cloned and sequenced. And the results of bioinformatics and molecular phylogenetics analyses with BioEdit 7.0, Clustal X 1.81 and Phylip 3.65 were as follows: (1) The sequences of cpcHID operon, 16S rRNA and ITS from the seven strains were highly homologous to the each corresponding gene based on multiple pair-wise comparison. (2) The mean absolute deviation of the G C content, the ratio of different sites and the genetic distance coefficient based on the sequences of cpcHID operon in the seven strains were generally greater than that based on 16S rRNA and ITS region. (3) The phylogenetic dendrogram based on the sequences of cpcHID operon was almost same with that based on the sequences of 16S rRNA and ITS region. Therefore, it revealed that cpcHID operon could be applied as a new molecular marker to classification and identification of cyanobacterium, and more appropriate for species or strains determination due to its abundant information.