Variation in the nucleotide sequences of a 16S rRNA gene fragment from cyanobacteria from picoplankton from Lake Baika from natural samples and laboratory cultures]

Nucleotide sequences were determined for the 16S rRNA gene 5T-terminal regions of 29 strains of picoplankton cyanobacteria from the lake Baikal in Russia and four strains from the lake Constance (Bodensee) in Germany. Sequences of a 387-bp region of the gene of cultivated strains designated A, B, C, D, and E had only a few (1-3) substitutions as compared with the 3-27 sequence of the clones obtained earlier by cloning from a pooled sample of Baikalian winter picoplankton. The specific 4-33 sequence obtained earlier from a dominant species of Baikalian picoplankton was not found in cultivated cyanobacteria.