Genetic Diversity and Population Structure of Bulgarian Autochthonous Sheep Breeds Revealed by Microsatellite Analysis

Abstract

This study attempts to provide a deeper insight into the current genetic status of 12 Bulgarian autochthonous sheep breeds using microsatellite (SSR) markers. A total of 600 individuals from 50 flocks were analyzed using a panel of 13 SSR markers. In total, 228 alleles were found in the studied microsatellite loci. The mean number of alleles, the effective number of alleles, and the polymorphic information content (PIC) values per locus were 17.54, 5.250, and 0.799, respectively. The expected heterozygosity (He) for all breeds ranged from 0.70 to 0.82. The within-population heterozygote deficit (Fis) varied from −0.03 to 0.1, reflecting significant levels for 10 of the 12 breeds. The average genetic differentiation (Fst) was 0.046, revealing a low discrimination between the breeds. The genetic distance, principal coordinate analysis, and the structure analysis showed that two of the studied breeds—Local Stara Zagora/SZ/ and Local Karnobat/MK/—were the most distinct sheep populations. The Bayesian clustering approach suggested poor breed differentiation for the remaining 10 sheep breeds. The results suggest that proper management strategies and specific breeding policies need to be implemented in Bulgaria to avoid the intermixing of breeds and to reduce the erosion of breed purity observed in some breeds.

Dynamics of some biochemical parameters in two local sheep breeds depending on the season, altitude and the presence of parasites

“…В днешни дни запазването на тези породи е национална политика, което определя сравнително по-широкият им ареал на разпространение, а успоредно с глобалните климатични промени е неизбежно те да претърпяват различни аклиматизационни промени, затова необходимостта от нови изследвания е с оглед да се отчетат адаптивните реакции на местните породи овце. Подобно изследване правят Mihailova et al (2023), които изследват генетичното разнообразие и популационната структура на 50 стада от 12 местни породи овце, включително двете местни породи, предмет на настоящото изследване и неизследвани досега. Установената от авторите ниска генетична диференциация между тези породи, успоредно с препоръките им за подо-бряване на селекционната политика, е причина за задълбочаване на изследванията и в други насоки, като хематологични и биохимични изследвания на стадата, които да вземат предвид и факторите на околната среда.…”

Mitochondrial Diversity and Phylogenetic Relationship of Eight Native Bulgarian Sheep Breeds

“…To date, the majority of studies on the genetic diversity among native Bulgarian sheep have been performed only on autosomal short tandem repeat variations (STR, microsatellites) [39][40][41][42][43][44]. In this research, carried out in 2023, we evaluated for the first time the genetic diversity of eight native Bulgarian sheep breeds which are threatened with extinction, based on the sequence polymorphism of the mitochondrial control region (D-loop region).…”