Molecular Phylogeny And Sequences Analysis Of Eight Microcystis Strains Using GyrB Gene And RpoC1 Gene

Microcystis, cyanobacteria that frequently occur as noxious blooms in eutrophic freshwaters, are of major concern because many strains produce cyclic heptapeptide toxins called microcystins, which threatens the ecosystem and the saefty of drinking water, also is a harzard to human health and is responsible for deaths in native and domestic animals.The traditional taxonomic methods of Microcystis have largely relied on the morphology, but there is scientific dispute about differentiating Microcystis on these traditional methods. It has been doubted when only using morphology to distinguish toxic and non-toxic strains. Morover, these methods are rather time-consuming.The use of molecular techniques enables investigation of the distribution of Microcystis in shorter time, also makes the results more accurate and reliable. Thus, the molecular techniques are becoming more popular in the differentiation of Microcystis.16S rDNA, 16S-23S rDNA ITS and PC-IGS have been used in phylogenic classification of Microcystis, they are common molecular markers of taxonomic researches and a number of results have been carried out. Nevertheless, there are some problems exist in each of these markers.Some studies reported that classification of several cyanobacteria received fine results by determining sequences within gyrB gene and rpoC1 gene. The use of tow genes for investigating bacteria is often assumed, but they have not so far been systematically used in the phylogenic classification of Microcystis. Therefore, we deceided to use thses two genes as molecular markers to analyze the relationship of phylogeny among Microcystis strains, which from three reservoirs and one lake.In this study, eight Microcystis strains including seven strains of Microcystis aeruginosa and 1 strain of Microcystis flos-aquae from different regions of China were analyzed. The regions were TangXi reservoir, ShaTin reservoir, HeDi reservoir in GuangDong province and TaiHu lake in JianShu province, all of the strains were compared to the related strains obtained from GeneBank.NJ and ME algorithms were used to construct phylogenic trees of the sequences, which amplified by gyrB and rpoCl genes. Derived phylogenetic trees revealed a close...