Thesis (M.Sc.) - Cairo University - Faculty of Veterinary Medicine - Department of Biochemistry and Chemistry of Nutrition

This study was carried out for detection of polymorphisms in melatonin receptor 1A (MTNR1A) and Arylalkylamine N acetyltransferase (AA-NAT) genes and their association with reproductive traits. Blood samples of 126 Animal from three Egyptian sheep breeds were collected. DNA was extracted and subjected to PCR-RFLP using RsaI and SmaI enzymes. Two alleles (C and T), three genotypes (CC, CT and TT) for MTNR1A gene also (A and G), (GG, GA, and AA) for AA-NAT gene were detected. Alleles C and A, genotypes CT and GA showed the highest frequency for MTNR1A and AA-NAT genes respectively. Association analysis of MTNR1A SNP revealed a significant association in Ossimi and Rhmani breeds with age of first lambing and C allele seems to be the favorable allele. Results for AA-NAT SNP demonstrate significant differences in Ossimi with age of first lambing and litter size and in Rhmani with lambing interval and Quite discrepancy were observed for the favorable allele. Concerning to first conception season the study revealed that ewes carrying CT genotype of MTNR1A gene and conceive in UF season exhibited significantly the lowest age of first lambing and TT ewes conceived in LF have the highest litter size

Issued also as CD