Faculty of Marine Science and Technology, Fukui Prefectural University.
Graduate School of Arts and Sciences, The University of Tokyo.
Microbes Environ. 2020;35(1). doi: 10.1264/jsme2.ME19110.
Microcystis aeruginosa was quantitatively surveyed in 88 freshwater environments across Japan within 3 weeks in 2011. In order to clarify the distribution pattern of M. aeruginosa at the intra-species level, three major genotypes, which were defined by 16S-23S rRNA inter-transcribed-spacer (ITS) regions, were selectively detected using quantitative real-time PCR assays. Of the 68 sites at which the Microcystis intergenic-spacer region of the phycocyanin (IGS-PC) gene was detected, the M. aeruginosa morphotype-related genotype (MG1) dominated in 41 sites, followed by the non-toxic M. wesenbergii-related genotype (MG3). A correlation analysis showed that total nitrogen and phosphate positively correlated with the abundance of IGS-PC, which positively correlated with microcystin synthetase gene abundance. A redundancy analysis of genotype compositions showed that pH positively correlated with the dominance of MG3 and negatively correlated with MG1, i.e., both toxic and non-toxic genotypes. Our survey of Microcystis populations over a wide area revealed that MG1 is a dominant genotype in Japan.
2011 年，在 3 周内对日本 88 个淡水环境中的铜绿微囊藻进行了定量调查。为了阐明种内水平铜绿微囊藻的分布模式，使用定量实时 PCR 检测方法选择性地检测了由 16S-23S rRNA 转录间隔区（ITS）定义的三种主要基因型。在检测到的 68 个微囊藻藻蓝蛋白（PC）基因间基因间隔区（IGS-PC）的位点中，铜绿微囊藻形态相关基因型（MG1）在 41 个位点占主导地位，其次是无毒的威氏微囊藻相关基因型（MG3）。相关性分析表明，总氮和磷酸盐与 IGS-PC 的丰度呈正相关，而 IGS-PC 的丰度又与微囊藻毒素合成酶基因的丰度呈正相关。基因型组成的冗余分析表明，pH 值与 MG3 的优势呈正相关，与 MG1 呈负相关，即有毒和无毒基因型均存在。我们对大面积微囊藻种群的调查表明，MG1 是日本的优势基因型。
