Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Biyolojik Bilimler Bölümü, Türkiye
Tezin Onay Tarihi: 2013
Öğrenci: İHSAN CİHAN AYANOĞLU
Danışman: İNCİ ZEHRA TOGAN
Özet:In the present study, it was aimed to contribute to the understanding of evolutionary history of sheep by using endogenous Jaagsiekte sheep retrovirus (enJSRV) integrations in 220 samples from 11 Turkish sheep breeds (Karayaka, Dağlıç, Kıvırcık, Sakız, Akkaraman, İvesi, Norduz, Karagül, Hemşin, Gökçeada and Morkaraman) and also in 30 samples from Anatolian wild sheep (Ovis gmelinii anatolica). Retrotypes of individuals were determined based on enJSRV integrations. The genetic distances between breeds were calculated and spatial distribution of retrotypes in Turkish sheep breeds have been determined by construction of synthetic maps. In the study it has been shown that all previously observed retrotypes for Turkish sheep breeds (R2, R4 and R6) were also present among the individuals of the present study. In addition to these retrotypes, previously non-observed retrotypes for Turkish breeds (R0, R1 and R7) were also observed in Turkish sheep breeds which have been examined in this study. Different retrotype frequencies for Turkish sheep breeds have been observed when compared to previous studies. Spatial distribution of retrotypes showed that Turkey was separated into two broad regions where the regions were represented by fat-tailed and thin-tailed sheep breeds, generally. Seven of 30 Anatolian wild sheep samples exhibited retrotype of primitive breeds (R0) and also some individuals exhibited a new retrotype where there are no enJSRV integrations for enJSRV-6 integration site which was assumed to be “fixed insertion” previously. Thus, the present study brings new insight into evaluation of enJSRV-6 integration which is to use this integration and suggests that it can also be used as a polymorphic integration site. Also, comparative studies of enJSRV markers with sex dependent (mtDNA and Y-linked) markers indicated that possible second migration of the sheep may be mediated by males. The present study examines the enJSRV polymorphismthat is present in Turkey with a high resolution. The results contributes to the understanding of the evolutionary history of sheep and gives insights about the shaping of the genetic diversity observed among domestic sheep over Turkey on the basis of enJSRV integrations. Furthermore, polymorphism in enJSRV-6 especially high frequency of newly observed allele is may be indicating an interesting event related with the sheep domestication.