[Divergence of unique DNA sequences of bivalve mollusks from Mytilinae subfamily (Bivalvia mytilidae)].

The DNA-DNA hybridization method was used to determine the divergence degree of unique sequences of five bivalvia species belonging to the Mytilinae subfamily. The matrix of delta Tm values for heteroduplexes of unique sequences was found which made it possible to define three phylogenetic branches within the subfamily. Under non-stringent hybridization conditions (55 degrees C, 0.5M PB) the divergence between species of any two branches was about 14% of nucleotide substitutions. The hybridization of [3H] unique sequences of Mytilinae with DNA fragments of Modiolus modiolus, a representative of the closest relative Modiolinae subfamily, showed that the divergence rate of unique sequences in two phylogenetic lines of the Mytilus genusis higher than in the line of the Crenomytilus genus I0.35-0.23% and 0.1% of nucleotide substitutions per one million years, respectively). According to the matrix of delta Tm values for five species of Mytilinae and Modiolus modiolus, a phylogenetic tree was built reflecting the differences between the divergence rates in different branches.