Genetic relationships among four Turkish sheep breeds using microsatellites

Abstract

IntroductionTurkey's proximity to domestication centers, along with its climate, topographical pattern, and agricultural structure that is formed according to plant cover, has created an appropriate environment for sheep breeding. Therefore, there are many sheep breeds in various regions and territories (1,2). Although there are many varieties and crossbred populations of sheep breeds in Turkey, 20 sheep breeds have been officially registered by the Ministry of Food, Agriculture, and Livestock (3). Even though Gökçeada (GA), Kıvırcık (KIV), Karacabey Merino (KM), and Sakız (SZ) sheep breeds, which are raised in the western Anatolian and Marmara regions, have a low percentage of native sheep population, each breed has certain significant characteristics. SZ sheep, known for their high fertility and milk production, and GA sheep, known for their milk production and high lamb survival rate, are raised along the coastline of the Aegean region. KIV and KM sheep breeds are known for their meat quality, wool, and meat production and are raised in western Turkey. For the purpose of improving the meat quality and fertility of the sheep population in western Turkey, the SZ and KIV breeds are commonly used in crossbreeding (4).Molecular genetic methods for identifying genetic structure and diversity in farm animals have shown a rapid development in recent years and have become widely used. Various molecular genetic methods have been developed for this purpose. Microsatellites that are specific to DNA regions are more widely used than other methods (5).This study aims to determine the genetic structure of GA and SZ sheep breeds, which are bred on the coastline of the Aegean region, and that of the KIV and KM sheep breeds, which are commonly bred in the Aegean and Marmara regions, by means of microsatellites. The information obtained from this study is based on microsatellite markers and will clarify the genetic relationships between these sheep breeds. It will also be helpful for determining current and future breeding programs and breed management and conservation strategies. Materials and methods Animal resources and DNA isolationThe animal material of the study consisted of a total of 250 animals belonging to GA, KIV, KM, and SZ sheep populations bred in the Aegean and Marmara regions. The origins and sample sizes of these 4 breeds are presented in Table 1. A DNA isolation kit (Applied Biological Materials Inc., Canada) was used for DNA extraction from blood samples.

Genetic diversity among Sawakni, Berberi and Najdi sheep breeds in Saudi Arabia using microsatellites markers

“…The mean observed heterozygosity values in the present study were 0.895, 0.938 and 0.719 for SW, BR and NJ sheep breeds, respectively, with a grand mean of 0.851. This value is higher than that reported by other studies of Indonesian sheep (0.574), Coimbatore sheep in India (0.625) Turkish sheep (0.66) and Colombian sheep (0.680) (Jakaria et al, 2012;Hepsibha et al, 2014;Yilmaz et al, 2015;Ricardo et al, 2016, respectively). On the other hand, the expected heterozygosity (He), the best estimator of genetic diversity in a population (Kim et al, 2002), was 0.782, 0.741 and 0.716 for SW, BR and NJ sheep, respectively, with a grand mean of 0.746.…”

“…It was higher than that observed by Pramod et al (2009) in Vembur sheep population of South India (2-9) and by Radha et al (2011) in Kilakarsal sheep population (3-12). Yilmaz et al (2015) found a range of 15 to 31 alleles per locus in Turkish sheep populations (Gökçeada, Kıvırcık, Karacabey Merino, and Sakız) whereas Ricardo et al Means of effective number of alleles implied by the three Saudi sheep populations, SW, BR and NJ, were 4.893, 4.192 and 3.781, respectively, with a grand mean of 4.289. Turkish sheep breed displayed higher mean effective number of alleles of 7.040 (Yilmaz et al, 2015).…”

“…Yilmaz et al (2015) found a range of 15 to 31 alleles per locus in Turkish sheep populations (Gökçeada, Kıvırcık, Karacabey Merino, and Sakız) whereas Ricardo et al Means of effective number of alleles implied by the three Saudi sheep populations, SW, BR and NJ, were 4.893, 4.192 and 3.781, respectively, with a grand mean of 4.289. Turkish sheep breed displayed higher mean effective number of alleles of 7.040 (Yilmaz et al, 2015). Balochi and Rakhshani sheep breed in Pakistan displayed the lowest average effective number of alleles of 2.969 (Wajid et al, 2014).…”

“…Black lines separate individuals of different clusters based on structure analysis, SW+BR and NJ. (Jakaria et al, 2012;Yilmaz et al, 2015;Ricardo et al, 2016, respectively). Interestingly, the lowest Ho was observed in SW sheep (0.400) in the OarFCB128 marker and the lowest value of He was in the MAF214 marker of NJ sheep breed (0.497).…”

“…Purity and concentration of each sample was quantified using NanoDrop 2000 spectrophotometer (Thermo Scientific, Wilmington, Delaware, USA). These markers were selected by taking into account the level of polymorphism previously detected in other studies and the location on different chromosomes (Peter et al, 2007;Ferrando et al, 2014;Yilmaz et al, 2015). Polymerase chain reaction (PCR) amplifications were carried out in a 25 µl reaction volume containing100 ng of template DNA and 2 µl of each 10 µM primer.…”