Patterns of evolution and migration in the arctic ground squirrel, Spermophilus parryii (Richardson)

Abstract
Serum transferrins and 11 other genetically controlled proteins representing 17 loci were examined by starch-gel electrophoresis from Siberian, Alaskan, and Canadian populations of Spermophilus parryii. Six transferrin alleles were identified. Arctic populations (S. p. parryii, S. p. osgoodi) were characterized by Tf 6 occurring alone or together with Tf 7 whereas middle and subarctic populations exhibited Tf 7 occurring either alone (S. p. ablusus, S. p. lyratus, S. p. plesius) or together with Tf 5 (S. p. plesius). Tf 8, Tf 9, and Tf 19 constituted local variants. Tf 6 displayed a clinal distribution, increasing in frequency eastward and paralleling a clinal increase in body size. Three PGM2 alleles were observed, the frequencies of which tend to differentiate arctic S. p. parryii from subarctic S. p. ablusus. G6PD-b occurred uniformly in North America and in one Siberian population; a second population (two specimens) exhibited G6PD-a, thereby suggesting that G6PD polymorphism may be present in Siberian S. parryii. The other nine proteins were monomorphic in all Holarctic populations.