Karyotypes and systematics of Asian high-mountain voles, genus <i>Alticola </i>(Rodentia, Arvicolidae)

Abstract

Six species/subspecies of Asian high-mountain voles, genus Alticola, were studied cytogenetically via conventional staining and C- and G-banding. The karyotypes are very similar. The standard karyotype, as in A. strelzovi strelzovi, consists of 56 chromosomes. These are split into 25 acrocentric pairs, one large subtelocentric pair, one small metacentric pair, a large acrocentric X chromosome, and a small Y chromosome, which varies in shape. Constitutive heterochromatin is almost entirely restricted to small centromeric regions. A small submetacentric pair of autosomes in both subspecies of A. semicanus and a medium-sized Y chromosome in A. argentatus severtzovi are of importance in systematics. The data suggest that A. barakshin, A. semicanus, and A. argentatus are separate species.

Voles and Lemmings (Arvicolinae) of the Palaearctic Region

“…The karyotype (2n=56) is uniform (known in argentatus, barakshin, semicanus, and strelzovi), This uniformity, along with the rarity of interspecific rearrangements, suggests a conservatively fixed karyotype (Hielscher et al 1992).…”

“…Karyotype is known in two subspecies (argentatus and severtzowi); diploid number is stable (2n=56) but the fundamental number varies (NF=58-62 ;Dimitriev 1990, Stubbe et al 1994. Heterosomes are acrocentric: the X is large and the Y is a medium-sized element (Hielscher et al 1992). Tribe: Clethrionomyini Hooper & Hart, 1962 77.…”

“…Although described as a species in its own right, in the past A. barakshin was regarded as conspecific with either stoliczkanus (Gromov & Polyakov 1977, Corbet 1978, Pavlinov & Rossolimo 1987, roylei (Heptner & Rossolimo 1968, Honacki et al 1982, or argentatus (Sokolov & Orlov 1980). Full species status was restored on the grounds of morphology (Rossolimo 1989b) and confirmed using karyotype (Hielscher et al 1992), allozymes (Hille & Stubbe 1996) and nucleotide sequences (Lebedev et al 2007. Crossbreeding trials of A. barakshin with semicanus and argentatus failed to produce interspecific hybrids (Stubbe et al 1994).…”

“…Karyotype (2n=56) has a polymorphic 1 st autosomal pair (subtelocentric or acrocentric), hence the fundamental number is variable (NFa=58-62); the small autosomal pair is invariably bi-armed. The X chromosome is large acrocentric and the Y is small metacentric (Hielscher et al 1992, Stubbe et al 1994).…”

“…M1 (length=2.00-2.75 mm; Pozdnyakov et al 2004) has 3-4 labial reentrant angles; the alternating triangles T1-T2 and T3-T4 are isolated or confluent; T5 is normally confluent with anterior cap which is either simple oval or with an additional labial triangle (T6); BR4 is rarely deep. Karyotype (2n=56, NFa=58) consists of 25 pairs of acrocentrics of variable size, 1 pair of large subtelocentric and 1 pair of small metacentric autosomes; X is large acrocentric and Y is small subtelocentric (Orlov & Bulatova 1983, Hielscher et al 1992, Stubbe et al 1994).…”