EN
The aim of the study was to evaluate the parameters of genetic variability at the MHC class II DRB1 and DQA1 loci in 112 brown hares from 4 regions of Poland. Disturbances in the Hardy-Weinberg (HW) equilibrium associated with an increase in homozygocity at these loci may lead to an increase in the proportion of females whose fetuses have compatible MHC haplotypes. This compatibility may result in abortion, which diminishes the reproductive success of the species. The extraction of nuclear DNA from peripheral blood Iymphocytes was performed with GenElute Blood Genomic DNA Kit manufactured by Sigma-Aldrich. DNA isolation from muscles was performed with Sherlock AX set manufactured by A&A Biotechnology. Primers and PCR conditions for the second DQA gene exon were conducted according to (34). Alleles obtained were analyzed for polymorphism by the SSCP method with modifications according to (34). The following primers were used to obtain exon 2 of the DRB gene: DRB2F 5’ - GAG TGT CAT TTC TAC AAC GGG A - 3 `, DRB2R 5’ - CTC CCG AAC CCC GTA GTT GTG TTT GC - 3’. Other reaction conditions were the same as for the DQ gene. Alleles obtained were analyzed with the Arlequin 3.5 program (20). The following parameters were analyzed: expected and observed heterozygocity, the inbreeding level (FIS), and the fixation index (FST). The number of alleles in the population, the number of private alleles, the number of homozygotes and heterozygotes, as well as the allelic richness (R) were determined with the FSTAT v.2.9.3.2 program (23). FIS for the DRB1 locus revealed an HW disequilibrium with a significant excess of DRB1 homozygotes, especially in the Kalisz region. FIS for the DQA 1 locus revealed an HW equilibrium in the Kalisz and Oświęcim regions, whereas in the other regions (Ciechanów and Płock) there was a slight excess of heterozygotes. These results are the first findings for the MHC class II DRB1 and DQA1 loci in a population of Polish hares living in the wild. The above picture of changes in the frequency of genes and DRB1 and DQA1 genotypes shows tendencies towards decreasing heterozygocity and increasing homozygocity. This reveals the local incidence of highly unfavorable phenomena associated with an inadequate gene exchange, resulting in a disturbed HW equilibrium. These findings suggest that poor reproductive performance of Polish hares may be indirectly related to a disturbed HW equilibrium and a significant increase of homozygocity at the MHC class II DRB1 locus.