Genetic Variability of CAST Gene in Native Sheep Breeds of Turkey

Abstract

The aim of this study is to determine the genetic variability of CAST gene in native sheep breeds of Turkey by PCR-RFLP method. Six different native sheep breeds; Kivircik, Imroz, Karayaka, Hemsin, Red Karaman and Karakul were used in this study. This study was the first report about CAST gene variation in Karayaka, Red Karaman and Hemsin sheep breeds. After DNA isolation and PCR amplification, RFLP was performed with MspI enzyme. Two alleles M (336bp and 286bp) and N (622bp) were identified on 2% agarose gel electrophoresis. Allel and genotype frequencies, observed (Ho) and expected heterozygosity (He) and deviation from Hardy Weinberg Equilibrium were estimated by statistical analyses. The frequency of M allele was highest in Imroz (96%) and N allele was identified most frequently in Kivircik (30%) breed. Highest frequencies of MN genotype were identified in Kivircik (60%), MM in Imroz (92.6%) and NN in Red Karaman (7.1%) breeds respecitvely. Kivircik, Imroz, Karayaka and Karakul breeds were null from NN genotype. Kivircik sheep showed the highest heterozygosity (60%) and Imroz had the lowest (7.4%). The highest heterozygosity value was identified in Kivircik (60%), the lowest in Imroz (7.4%). All breeds except Kivircik and Hemsin were found in Hardy-Weinberg equilibrium. Absence of NN genotype in some breeds and high frequency of MN genotype in Kivircik breed might be resulted from the selection process of native sheep breeds in their breeding regions.