Genetic relationships and evolutionary history of extant Bowhead whale populations, Balaena mysticetus

Bowhead whales, Balaena mysticetus, are large baleen whales that are characterized by an Arctic distribution. In order to provide proper management recommendations to the International Whaling Commission, a panel of twenty-five microsatellite markers was developed. This panel consisted of pure cytosine-adenine (CA) repeats and was selected for their ability to consistently amplify and for their consistency for allele designations. This panel was utilized to investigate stock structure within the Bering-Chukchi-Beaufort population of bowheads. Over thirty reports and manuscripts utilized these data for providing management recommendations to the International Whaling Commision. From this work it was concluded that there is presently one stock of bowhead whales within the Bering-Chukchi-Beaufort seas. This data was also utilized to examine the genetic relationships of the remaining extant bowhead populations. The microsatellite data, in combination with sequences from the mitochondrial control region and the NADH dehydrogenase subunit 1 (ND1) region, were used to examine population structure. The Okhotsk Sea was identified as the most divergent population of bowheads. Relationships among the extant populations demonstrated high levels of effective gene flow between populations. Gene flow appeared to be female-biased in relation to the Okhotsk Sea, whereas gene flow between Canada and the Bering-Chukchi-Beaufort populations appears to be equal between the bowhead whale sexes.