SPATIAL STRUCTURE OF THE LIPIZZAN HORSE GENE POOL BASED ON MICROSATELLITE VARIATIONS ANALYSIS

Abstract

The aim of this study was to determine the current state of genetic diversityand to assess the substructure and spatial structure at individual level based onanalysis of microsatellite variations within Lipizzan horse population. The genomicDNA samples were obtained from totally 418 horses, originating from Slovenian(357) and Slovak (61) studs. A set of 13 microsatellite markers (AHT4, AHT5,ASB2, HMS1, HMS2, HMS3, HMS6, HMS7, HTG10, HTG4, HTG6, HTG7, andVHL20) have been used for analysis of genetic variability. Across all microsatelliteloci the average number of alleles 6.65 and effective allele number at level 3.37were found. The obtained Shannon's information index (I=1.37) indicated highdegree within population genetic diversity. The prevalence of heterozygousgenotype in sample confirmed also the average value of observed heterozygosity(Ho=0.67) and FIS index (-0.026). The most of the genetic variation in sample wasconserved within individuals (95%) and the subdivision of horse populationsexplained only 4%. Similarly, the obtained pairwise values of FST index (0.02) andNei's genetic identity (0.90) reflected mainly common ancestors used in breedinghistory of both population. But the principal coordinate analysis showed thedivision of individuals into the two separate clusters according to the studs wherethey come from. The membership probability resulted from spatial structureanalysis suggested that the frequencies of alleles varied across the two regions thatindicated the evidence of strong distinction in relation to the current breeding statusof analysed populations and strategy of studs.