Genetic diversity and bottleneck analysis of the Red Steppe cattle based on microsatellite markers

Abstract

Thirty-nine dairy cows representing the Red Steppe (RS) cattle breed (the State Enterprise “Pedigree Reproducers “Stepove” Mykolayiv region, Ukraine) were included in the study. A set of 11 microsatellite markers recommended by International Society of Animal Genetics (ISAG) for cattle was used to study genetic diversity in the RS cattle population. All of the studied loci were highly informative and polymorphic. In total, 71 alleles were detected at 11 microsatellite loci, from which 16 (22.5%) had frequency lower than 5%. The number of detected alleles per locus (TNA) ranged from four to ten, with a mean value of 6.45±0.51. The mean effective number of alleles (Ae) was 3.77±0.37. The allele frequencies ranged from 0.013 to 0.714. The average values for observed (Ho) and expected (He) heterozygosities were 0.607±0.085 and 0.703±0.034, respectively. The within breed estimate FIS indicates heterozygosity shortage of 0.179. The Hardy-Weinberg equilibrium test revealed that 2 out of 11 loci deviated from equilibrium. The RS cattle population is non-bottlenecked, i.e., it has not undergone any recent reduction in the effective population size and remained at mutation-drift equilibrium. The estimated mean Ne for the RS cattle population was 23.3 (95% CIs = 11-74) individuals. These low values emphasize the need of controlling the rate of increase of inbreeding in the RS cattle herds.