Signs of Selection in Synonymous Sites of the Mitochondrial Cytochrome b Gene of Baikal Oilfish (Comephoridae) by mRNA Secondary Structure Alterations.

Studies over the past decade have shown a significant role of synonymous mutations in posttranscriptional regulation of gene expression, which is particularly associated with messenger RNA (mRNA) secondary structure alterations. Most studies focused on prokaryote genomes and the nuclear genomes of eukaryotes while little is known about the regulation of mitochondrial DNA (mtDNA) gene expression. This paper reveals signs of selection in synonymous sites of the mitochondrial cytochrome b gene (Cytb) of Baikal oilfish or golomyankas (Comephoridae) directed towards altering the secondary structure of the mRNA and probably altering the character of mtDNA gene expression.

Molecular divergence and speciation of Baikal oilfish (Comephoridae): facts and hypotheses.

Sympatric speciation was studied in two sister species of cottoid fish from Lake Baikal (East Siberia): big golomyanka or Big Baikal oilfish (Comephorus baicalensis Pallas, 1776) and small golomyanka or Little Baikal oilfish (C. dybowski Korotneff, 1905). Analysis of nucleotide sequences of mitochondrial cytochrome b gene showed that the Little Baikal oilfish (LBO) formed a single population in the lake, whereas the Big Baikal oilfish (BBO) was divided into two genetic groups - BBOI and BBOII, which were not separated geographically.