ISSN 1022-7954, Russian Journal of Genetics, 2008, Vol. 44, No. 9, pp. 1105–1110. © Pleiades Publishing, Inc., 2008.
Original Russian Text © I.G. Meschersky, M.V. Kholodova, E.Yu. Zvychaynaya, 2008, published in Genetika, 2008, Vol. 44, No. 9, pp. 1268–1274.
Beluga whale (
) is a toothed
whale of medium size native to cold (Arctic, Subarctic,
and, to a much lesser degree, temperate) waters on the
northern hemisphere. In summer, groups of beluga
whales come to feeding areas, most of which are rela-
tively shallow waters along coasts; as it becomes colder
and ice conditions deteriorate beluga whales migrate to
the open sea, where they stay in areas free of consoli-
dated ice ﬂoes.
The intraspeciﬁc organization and population struc-
ture of the beluga whale remain largely unclear. In the-
ory, the high mobility characteristic of cetaceans,
together with the ability of beluga whales “to move
across large sheets of dense, apparently consolidated
ice” , allows beluga whales to move freely all over
the species range. At the same time, the occurrence of
beluga whales substantially varies in different regions.
Therefore, some authors believe that the species is not
subdivided into distinct populations within the circum-
polar range , while others assume that there are from
5–8 to 29 separate groups (stocks) [1, 3–5]. If the latter
is actually the case, then the putative boundaries that
play the main role in restricting gene ﬂows between
populations are likely to run through the Greenland and
East Siberian seas, the center of the Canadian Arctic
Archipelago, and possibly the northern Paciﬁc Ocean.
The situation is complicated by the lack of unambig-
uous data on the timing (and, hence, regions) of beluga
whale mating, the long mating season, and the possible
variation of the timing of reproduction in different parts
of the range [1–3, 6]. If mating occur in wintering
regions or spring migration paths [1–3], there are wide
possibilities of gene exchange between groups of ani-
mals summering in different regions. Conversely, if
beluga whales mate in summer feeding regions [6–7],
their groups are expected to be genetically isolated.
Detailed molecular genetic data on the beluga
whales summering near American coasts both west and
east of the Canadian Arctic Archipelago were obtained
recently [3, 4, 8–11, etc.]. However, there are no such
data for other regions, in particular, Russian territorial
waters. In this study, we analyzed the nucleotide
sequences of the mtDNA control region of beluga
whales summering in the southern Sea of Okhotsk and
compared the results with published data on beluga
whales from other regions.
MATERIALS AND METHODS
Fragments of skin epidermis served as the material.
Samples of it were biopsied from 28 animals captured
during an expedition of Utrish Dolphinarium near
Baidukov and Chkalov islands in Sakhalin Gulf in the
months of August and September of the years 2004 and
2005 for research and educational purposes (Amurryb-
vod Administration for the Protection and Reproduc-
tion of Fish Reserves and Regulation of Fishing
Licenses no. 023037 of August 4, 2004 and no. 023527
of August 23, 2005). The samples were ﬁxed and stored
in 96% ethanol.
A Diatom DNA Prep 100 kit (Izogen, Russia) was
used for DNA isolation, and a Gene Pak PCR Core kit
(Izogen, Russia) and
Mix-2025 kit (Dialat,
Russia), for polymerase chain reaction (PCR) as rec-
ommended by the manufacturers.
For amplifying the mtDNA control region, we used
the primers (L15926 and H00651) and the PCR proﬁle
described in , except that the additional ampliﬁca-
tion stage was omitted. The sequencing of the control
Molecular Genetic Study of the Beluga (
Cetacea, Monodontidae) Summering in the Southern Sea
of Okhotsk as Compared to North American Populations
I. G. Meschersky, M. V. Kholodova, and E. Yu. Zvychaynaya
Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, 119071 Russia;
Received March 19, 2007
—The structure of the left part of the mtDNA control region has been studied in
captured in summer in the southern Sea of Okhotsk. The data have been compared with published results
of similar studies on
at different sites along the American coast. A high speciﬁcity of maternal lineages
from the southern Sea of Okhotsk has been demonstrated against the background of its historical connection
with the form from the Paciﬁc refugium that colonized the western Arctic region in postglacial time.