Genetic Variations and Bottleneck Demographic Studies in Kurdish Horse Breed Using ۱۷ Microsatellite Markers

The Kurdish horse is one of the most valuable and original pure genetic reserves in Iran. According to historical evidence, this breed dates back to more than ۲,۵۰۰ years ago. In this population, genetic variations were analyzed using ۱۷ microsatellite markers recommended by International Society for Animal Genetics (ISAG). Genomic DNAs were extracted from the hair roots of ۷۶۱ Kurdish horses. DNA fragments were amplified by multiplex PCR reaction using fluorescently labeled primers, and determined by capillary electrophoresis. Average number of alleles per locus was ۴.۲۹ (from ۶ alleles in HTG۷ to ۱۷ alleles in ASB۱۷). The mean value of the observed heterozygosity was ۰.۷۲۱, ranging from ۰.۴۹۱ (HTG۷) to ۰.۸۳۸ (VHL۲۰), while expected heterozygosity ranged from ۰.۵۲۳ (HTG۷) to ۰.۸۳۹ (VHL۲۰) with a mean of ۰.۷۵۲. The PIC value was from ۰.۷۰۸ (HMS۶) to ۰.۸۵۶ (ASB۱۷) with a mean of ۰.۷۸۲. The inbreeding coefficient ranged from -۰.۰۱۲ (ASB۲) to ۰.۱۸۳ (HTG۶) with a mean of ۰.۰۴۰. Deviation from Hardy-Weinberg equilibrium (P< ۰.۰۵) was found in ۱۱ loci. The total exclusion probability of the ۱۷ microsatellite loci was ۰.۹۹۹۹. Kurdish horse revealed bottleneck event under two models of microsatellite evolution for sign and standardized differences for Infinite Alleles Model (IAM) and Stepwise Mutation Model (SMM). Based on this study, the effectiveness of ۱۷ microsatellite markers for parentage verification and assignment test of Kurdish horse is confirmed. These results may facilitate conservation programs for the studied breeds and raise preserve their genetic variation.

Keywords:

Bottleneck effect , Genetic reserves , Infinite Alleles Model , Stepwise Mutation Model.