Sequence variability of the mitochondrial DNA cytochrome b gene in dolly varden char and taranetz char

Nucleotide sequence of the 307-bp fragment of the mitochondrial DNA cytochr ome b gene was determined in representatives of the three species of the Sa lvelinus genus, specifically, dolly varden char (S. malma), taranetz char ( S. taranetzi), and white-spotted char (S. leucomaenis). These results point ed to a high level of mitochondrial DNA (mtDNA) divergence between white-sp otted char and dolly varden char, on the one hand, and taranetz char, on th e other (the mean d value was 5.45%). However, the divergence between the d olly varden char and taranetz char was only 0.81%, which is comparable with the level of intraspecific divergence in the dolly varden char (d = 0.87%) . It was shown that the dolly varden char mitochondrial gene pool contained DNA lineages differing from the main mtDNA pool at least in the taranetz c har-specific mitochondrial lineages. One of these dolly varden char mtDNA l ineages was characterized by the presence of the restriction endonuclease M spI-D variant of the cytochrome b gene. This lineage was widely distributed in the Chukotka populations, but it was not detected in the Yana River (Ok hotsk sea) populations. These findings suggest that dolly varden char has a more ancient evolutionary lineage, diverging from the common ancestor earl ier than did taranetz char.