Complete mitochondrial genomes of Baikal endemic coregonids: omul and lacustrine whitefish (Salmonidae:Coregonussp.)

Abstract

Coregonid fishes are among the most successful groups in the subarctic, boreal, and subalpine fresh waters of the northern hemisphere. Limnetic-benthic sympatric species-pairs from two different evolutionary lineages, the North American lake whitefish (Coregonus clupeaformis species complex), and the European whitefish (Coregonus lavaretus species complex), are becoming the subject of close attention to explore the role of natural selection during the ecological speciation. Baikal endemic coregonids, limnetic omul (Coregonus migratorius), and benthic lacustrine whitefish (Coregonus baicalensis) are the only representatives of another unique lineage that has not left the lake since the divergence from the two above. Due to Pleistocene oscillations sympatric limnetic-benthic divergence has been replicated here many times within the same water body over a long geological period in contrast to both Europe and America where sympatric species-pairs are the results of post-glacial secondary-contacts between glacial isolates during the Late Pleistocene on the territory of each continent. Mitochondrial genomes encode genes that are essential for respiration and metabolism. Data on complete mitogenomes of Baikal endemic coregonids provided here will complement ongoing investigations on energy metabolism as the main biological function involved in the divergence between limnetic and benthic whitefish.

Salmonidae Genome: Features, Evolutionary and Phylogenetic Characteristics

“…In contrast to Europe and America, where morphologically similar species pairs are the consequence of postglacial secondary contacts between glacial isolates, sympatric limnetic-benthic divergence was repeated here several times within the same body of water over a long geological period due to Pleistocene fluctuations. According to cytb mtDNA, phylogenetic analyses indicated the interspecific linkages described for Baikal whitefish [ 342 ]. Comparative genetic ranges across the three lines of responsibility: Baikal endemics, North American lake whitefish, and European whitefish, imply comparable ages [ 343 ].…”