Genetic diversity of native and crossbreed sheep breeds in Anatolia


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Biyolojik Bilimler Bölümü, Türkiye

Tezin Onay Tarihi: 2004

Öğrenci: EVREN KOBAN

Danışman: İNCİ ZEHRA TOGAN

Özet:

In this study the genetic diversity in Turkish native sheep breeds was investigated based on microsatellite DNA loci. In total, 423 samples from 11 native and crossbreed Turkish sheep breeds (Akkaraman, Morkaraman, Kivircik, Ivesi, Dagliç, Karayaka, Hemsin, Norduz, Kangal, Konya Merinosu, Türkgeldi) and one Iraqi breed (Hamdani) were analyzed by sampling from breeding farms and local breeders. After excluding close relatives by Kinship analysis, the genetic variation within breeds was estimated as gene diversities (HE), which ranged between 0.686 and 0.793. The mean number of observed alleles (MNA) ranged between 5.8 and 11.8. The allele frequency distribution across Turkey showed no gradient from east to west expected in accordance with the Neolithic Demic Diffusion model. The differentiation between different samples of Akkaraman, Dagliç and Karayaka breeds was tested by FST index. Akkaraman1 sample from the breeding farm was significantly (P<0.001) different from the other two Akkaraman samples. Deviation from HW expectations observed for Akkaraman1, Ivesi, Morkaraman and Hemsin breeds. AMOVA analysis revealed that most of the total genetic variation (~90%) was partitioned within the individuals. In parallel to this observation, when factorial correspondence analysis and shared alleles distances were used to analyze the relationship between the individuals of the breeds, there was no clear discrimination between breeds. Moreover, NJ tree constructed based on DA genetic distance, and PC analyses were used to analyze among breed differentiation. Delaunay Network drew 4 genetic boundaries (two of them being parallel to geographic boundaries) between breeds. All the results indicated that Kivircik was the most differentiated breed. Finally, Mantel Test and Bottleneck analysis did not reveal a significant result. Kivircik breed, among all native Turkish breeds, was