ИСТИНА

Introduction: Genus Spermophilus, widespread in the former USSR, is known for the difficulty of its tax-onomy because its different species can live side-by-side and produce hybrid fertile offspring. The species status of related groups remains a subject of debate. As a result, the borders of their ranges are not yet fully understood. Molecular genetic studies are the most efficient approach for research of this group because they allow detection of traces of hybridization that may not be noticed by studying morphological or acoustic markers. Our study clarifies the borders of the ranges of two species of ground squirrels in northern Kazakhstan. In our analysis we used samples collected during an expedition to the Karaganda region of Kazakhstan. Methods: We amplified and sequenced part of the C-region of mtDNA of 87 animals from 29 points and the sixth intron of the p53 gene of 108 animals from 34 points from the Karaganda region. The results were plotted on a map. The data processing for the control region was carried out using the program MEGA6. A Test Maximum Likelihood Tree was plotted Results: On the phylogenetic tree plotted based on the obtained sequences, samples were divided into two groups: Little (Spermophilus pygmaeus) and Red-cheeked ground squirrels (S. erythrogenys). Most colo-nies contained animals that belonged to one of the species, but on the southern border of the Little ground squirrels’ range, two species were observed living close to each other with evidence of their hybridiza-tion. In addition, the following hybrids were found: 3 first-generation hybrids (probably belonging to one litter), whose father was a Red-cheeked ground squirrel and whose mother was a Little ground squirrel; 5 cases of mismatched nuclear and mitochondrial markers (3 introgressions of mtDNA of Little ground squirrel and 2 of Red cheeked ground squirrel); and a complex hybrid whose ancestors included Little, Red-cheeked and Yellow ground squirrels.