Genetic variation of the striped hamster (Cricetulus barabensis) and the impact of population density and environmental factors

The striped hamster ( Cricetulus barabensis ) is a dominant rodent species in the North China Plain and has suffered a continuous decline of population size in the last 17 years. However, little is known about the population genetic structure of this species and how it is influenced by geographical and environmental factors. In the present study, we investigated the genetic diversity and genetic differentiation of the striped hamsters in four geographical populations of different environmental features. The genetic variability for a sample of 158 animals from the four populations was estimated using data from 10 microsatellite loci. Genetic diversity exists in the striped hamster. The number of alleles and the proportion of heterozygosity indicate moderate variability. A total of 46 alleles were detected, with a moderate mean number of alleles. Significant genetic differentiation ( p < 0.01) exists among all four examined geographical populations. Population-specific alleles and variable allelic richness were detected in all populations regardless of the geographical distances. The genetic diversity positively correlates with the population density, while the genetic distance is partially affected by the geographical distances. Moreover, the habitat environment is also an important factor influencing the genetic differentiation of the species. The genetic diversity of the striped hamster is mainly impacted by population density, while partially influenced by geographical distances. The results of our study and other studies collectively suggest that a minimum geographical distance is required to prevent gene flow between different populations and for genetic differentiation to be pronounced.