Microsatellite Genotyping of Two Bulgarian Sheep Breeds

Tsonka Odjakova,Georgi Radoslavov,Peter Hristov,Pavel Todorov

doi:10.3390/d14030210

Abstract

The aim of this study was to compare the genetic structure and genetic diversity of two Bulgarian sheep breeds. A total of 41 individuals from a modern Bulgarian sheep population (Rhodopean Tsigai, RT) and 46 representatives of a local Bulgarian sheep population (Middle Rhodopean Sheep, MRS) were investigated based on 12 STR (short tandem repeat, also known as microsatellite) markers. In total, 121 alleles were found in the two populations using 12 microsatellite loci. The mean number of alleles, the effective number of alleles, and the polymorphism information content (PIC) values per loci were 10.08, 4.96, and 0.73, respectively. When comparing the allelic diversity across the populations, the highest Na was observed in the MRS breed (10.58 ± 0.87), while the value of this parameter in the RT breed was 9.58 ± 0.71. The largest genetic diversity was found at locus INRA005 with 14.5 alleles and the smallest polymorphism was noted for locus ETH152 with 5.5 alleles. The level of observed heterozygosity was in the range of 0.60 to 0.860. The expected heterozygosity level range was 0.62 to 0.87. When 12 microsatellite loci were compared, the INRA005 locus showed the highest level of genetic variability. Using Nei’s standard genetic distance, the observed genetic distance between the RT and MRS breeds was 0.103. Both sheep breeds demonstrated mixed genetic profiles based on the studied microsatellite markers. The clustering obtained by STRUCTURE analysis showed that the MRS breed is a more homogenous population, whereas the RT breed is more heterogenous.

Highlights

Considering the ever-changing dynamics of today’s reality, it is hard to anticipate what kind of animal breeds will be necessary tomorrow, what their productivity will be, what human needs for food substances should be provided for, and what will be required by the society and the common people thereof [1–3]
The diversity in terms of nature and climate conditions in the different regions of the country has contributed to the creation of a significant number of indigenous breeds adapted to specific local conditions [8,9]
A total of 87 blood samples were collected from one indigenous and one modern sheep breed, 41 of which were taken from the Rhodopean Tsigai (RT) and 47 from the Middle Rhodopean Sheep (MRS)

Summary

Introduction

Considering the ever-changing dynamics of today’s reality, it is hard to anticipate what kind of animal breeds will be necessary tomorrow, what their productivity will be, what human needs for food substances should be provided for, and what will be required by the society and the common people thereof [1–3]. Scientists keep on proving the beneficial effect of climatic and natural conditions upon the wholesomeness of animal production and, respectively, upon human health. The most important goal regarding animal breeds in future is to ensure that they are highly resistant to diseases and very well adapted to the conditions in every region, including the typical plant resources, so that breeds can express their production qualities in the best possible way [4,5]. Preservation of genetic diversity, especially in the context of breeding sheep that are well adapted to local conditions, resistant to diseases, healthy, and yielding milk, isrelated to the thousands of years long process of agriculture throughout the history of ancient human civilization [6,7]. The diversity in terms of nature and climate conditions in the different regions of the country has contributed to the creation of a significant number of indigenous breeds adapted to specific local conditions [8,9]. In Bulgaria, there are around 34 breeds of sheep, 17 of which are defined as autochthonous [10,11]

Objectives

Methods

Conclusion