Supernumerary Chromosomes Enhance Karyotypic Diversification of Narrow-Headed Voles of the Subgenus Stenocranius (Rodentia, Mammalia).

The subgenus Stenocranius contains two cryptic species: Lasiopodomys gregalis (subdivided into three allopatrically distributed and genetically well-isolated lineages A, B, and C) and Lasiopodomys raddei. To identify karyotype characteristics of this poorly studied cryptic species complex, we used comparative cytogenetic analysis of 138 individuals from 41 localities in South Siberia and Mongolia. A detailed description of the L.

Molecular systematics of the species complex: a contribution from historical DNA analysis.

The Tianshan birch mouse is an endemic of the Central Asian mountains and has previously been shown to include several karyomorphs ("Terskey", "Talgar", "Dzungar"); however, the taxonomic status of these forms has remained uncertain. We examined the genetic variation in based on historical DNA samples from museum collections, including the type series. Mitochondrial and nuclear data indicated that the species complex includes two major clades: Northern (N) and Southern (S) ( distance 13%).

Complex Structure of Sex Chromosomes, Sex Determination, and Intraspecific Autosomal Polymorphism.

The mandarin vole, , is one of the most intriguing species among mammals with non-XX/XY sex chromosome system. It combines polymorphism in diploid chromosome numbers, variation in the morphology of autosomes, heteromorphism of X chromosomes, and several sex chromosome systems the origin of which remains unexplained. Here we elucidate the sex determination system in using extensive karyotyping, crossbreeding experiments, molecular cytogenetic methods, and single chromosome DNA sequencing.