Intra-specific phenotypic and genotypic variation in toxic cyanobacterialMicrocystisstrains

Abstract

Aims: We determined if the intra‐specific genetic diversity of Microcystis aeruginosa correlates with phenotypic characteristics. Methods and Results: Microcystis aeruginosa isolates from various Japanese waters were characterized using genetic analyses based on the 16S–23S rDNA internal transcribed spacer (ITS) region and DNA‐independent RNA polymerase (rpoC1) gene sequences. In addition, morphological and biochemical properties, and the toxicity of M. aeruginosa strains were determined. We found a correlation in phylogenetic clusters of the ITS region and rpoC1 gene sequences. Using a polyphasic approach, genotypic and phenotypic variations in M. aeruginosa showed that the three genetic lineage groups are comprised of a particular phenotype or subgroup of closely related phenotypes. However, some strains had high phenotypic and genotypic diversity compared to the three lineage groups and did not show distinct lineages; therefore, these strains were designated as the ‘complex group’. Conclusions: The ‘complex group’ consisted of genetically and phenotypically incoherent and high diverse populations in M. aeruginosa, although some genotypes or lineages displayed consistent phenotypes. Significance and Impact of the Study: The polyphasic approach combining phenotypic and genetic characterization was effective for comprehending distinct lineages and discriminating the potential complexity of M. aeruginosa populations at the intra‐species level.

Polyphasic characterization of a thermo-tolerant filamentous cyanobacterium isolated from the Euganean thermal muds (Padua, Italy)

“…The 16S rRNA phylogenetic analysis confirms the results of the most recent phylogenetic analyses on Leptolyngbya (Casamatta et al, 2005;Yoshida et al, 2008;Bruno et al, 2009). Furthermore, most of the sequences reported in GenBank for strains identified as Leptolyngbya species have not been accompanied by morphological, ultrastructural, biochemical or eco-physiological data (Koma´rek & Anagnostidis, 2005;McGregor, 2007).…”

“…Similar data have been obtained with M. aeruginosa strains by Yoshida et al (2008) using a polyphasic approach, combining phenotypic and genetic characterization. This approach is effective for defining distinct lineages and discriminating the complexity of intra-specific populations.…”

Ecological Dynamics of the Toxic Bloom-Forming Cyanobacterium Microcystis aeruginosa and Its Cyanophages in Freshwater

“…At the nucleotide level, 10 differ- (27). We recently reported that M. aeruginosa populations have a high degree of genetic diversity at the intraspecies level (31), and their successional blooms revealed different dynamics during the bloom in Lake Mikata (33). We speculate there are various host-phage systems in the relationships between M. aeruginosa and its phages.…”

Intricate Interactions between the Bloom-Forming Cyanobacterium Microcystis aeruginosa and Foreign Genetic Elements, Revealed by Diversified Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) Signatures

“…Separately, we determined partial CRISPR sequences from eight M. aeruginosa strains isolated from the same pond water sample. The eight strains were identified as M. aeruginosa based on specific PCR targeting partial 16S-23S rRNA gene internal transcribed spacers (55). Two strains had a spacer set identical to that of CT1, another two strains were CT4, and another one strain was CT3.…”