Asaad Y. Ayied, Bashar F. Zaqeer
Abstract: This study was conducted at the Genetic Engineering Laboratory/College of Agriculture/University of Basrah. It aimed at the measuring the genetic polymorphism of the ND5 gene within the mitochondria of Awassi sheep and its relation to milk yield and the growth of lambs before weaning. A total of 87 sheep was used, in addition to their single lambs. Blood and milk samples were collected from ewes every 2 weeks till the age of weaning. Lambs were weighed from one day to the end of the weaning age once each fortnight. DNA was extracted from the blood and PCR technology was used to amplify ND5 factor. The Alignment sequences were lined up and aligned with the sequences of ND5 gene published within the National Biotechnology info Centre (NCBI). Haplotype and nucleotide diversities, Analysis of Molecular Variation (AMOVA) and haplotype network were established and evolution tree was constructed. ND5 gene showed thirty-seven polymorphism forms in the Awassi sheep breed. The diversity of the haplotype (HD) and the nucleotide diversity () of the were high (0.942, 0.01563 respectively). Total number of haplotypes (H) were 21 for different breeds of sheep used in this study, while that of Awassi was 13. The number of haplogroup was four and evolution tree showed 3 main branches among sheep breeds in different countries, Awassi sheep showed separate branch. The results of the molecular variation AMOVA revealed that the variation within the breeds is larger than the variation between breeds (21.93 % and 78.07 % respectively). The overall average milk production, birth weight and weaning weight were 522.99 g, 4.52 kg, and 17 kg respectively. ND5 polymorphism has a significant effect on weaning weight, however, its effect was insignificant on milk yield and its chemical components.
Keywords: ND5, Mitochondria, Awassi sheep, Genetic polymorphism