DGAT1, CAST and IGF-I gene polymorphisms in akkaraman lambs and their effects on live weights up to weaning age

Abstract

Early live weight in sheep is important for lamb survival and average weight gain until slaughter. The aim of the present study was to investigate association between CAST-MspI, DGAT1-AluI and IGF-1-Bsp143II polymorphisms and early live weights between birth and weaning age in Akkaraman lambs. A total of 374 lambs were genotyped for CAST-MspI, DGAT1-AluI and IGF-1-Bsp143II polymorphisms by the polymerase chain reaction and restriction length polymorphism (PCR-RFLP) method. The results of PCR-RFLP analysis showed that the SNPs had three genotypes of CAST-MspI polymorphism, two genotypes of DGAT1-AluI polymorphism and one genotype of IGF-1-Bsp143II polymorphism of these, CAST-MspI-MM, DGAT1-AluI-CC and IGF-1-Bsp143II-BB were the predominant genotypes in the Akkaraman sheep breed. The result of Chi-square analysis indicated that the Akkaraman sheep breed was in Hardy-Weinberg equilibrium for the investigated polymorphic genes. At the DGAT1 locus, the CT genotype showed significantly heavier birth weight (P=0.044) compared to CC genotype. CAST gene did not show any association for the investigated traits. The results of this study demonstrate that the CT genotype had a positive effect on birth weight in Akkaraman sheep. We concluded that further investigations are needed in DGAT1-AluI polymorphism and live weight at different ages in sheep.