阿氏浮丝藻mcyT基因序列多样性研究

为研究我国浮丝藻（Planktothrix Anagnostidis et Komrek）的毒素相关基因，选取分离自我国不同省份水体的13株阿氏浮丝藻，通过PCR检测其微囊藻毒素合成酶基因mcyA、mcyE及mcyT研究其毒素基因特性。PCR结果表明除mcyT之外其他引物检测均无扩增产物，说明这13株浮丝藻不具备产微囊藻毒素的能力。通过克隆测序得到mcyT序列，并进行分子系统分析，构建了关于mcyT序列的Neighbor-Joining系统树，结果表明mcyT序列可以将产毒与不产毒浮丝藻分为两大独立的分支，两个分支之间的最低序列相似度分别为98.5%和99.1%。研究结果可为后续研究我国浮丝藻的微囊藻毒素合成相关基因的多样性以及分子监测提供参考。  

PHYLOGENETIC STUDY BASED ON MCYT GENE OF PLANKTOTHRIX AGARDHII FROM CHINA

In this study, thirteen strains of Planktothrix agardhii from the freshwaters in different provinces were examined to detect the sequences of the synthetase genes of microcystins, including mcyA, mcyE and mcyT. The PCR results showed that only mcyT gene was amplified in these strains, indicating that these strains are not microcystin producers. The phylogenetic analysis based on the mcyT gene demonstrated that the Planktothrix strains were divided into two clades in the Neighbor-Joining tree, well corresponding to the non-toxic and toxic strains, and the minimum similarity of the two clades were 98.5% and 99.1%. The results provided a new insight into the molecular divergence between toxic and non-toxic Planktothrix strains.