Association between MTNR1A and CYP19 Genes Polymorphisms and Economic Traits in Kurdi Sheep

The ovine melatonin receptor 1A (MTNR1A) and aromatase (CYP19) genes were structurally characterized and the association between their variants and reproductive and growth traits was studied in Kurdi sheep at Kurdi sheep breeding station located in Shirvan, Iran. The genomic DNA was extracted by guanidine thiocyanate-silica gel method. Polymerase chain reaction was carried out to amplify 824 bp fragment of exon 2 of MTNR1A and 140 bp fragment of the exon 3 of the ovine CYP19 genes. The PCR products were digested with restriction endonucleases RsaI for MTNR1A and BstMBI for CYP19 genes and checked by polyacrylamide gel electrophoresis for the presence of restriction sites. Two alleles were found for all the loci investigated, which were named as A and B for CYP19, and R and r for MTRN1A. Allelic frequencies for MTRN1A were 0.49 and 0.51 for R and r alleles, while in the case of CYP19 gene, frequencies were 0.475 and 0.525for A and B alleles, respectively. Association analysis did not show any significant relations between MTNR1A gene polymorphisms and litter size (LS), age at first lambing (AFL) and lambing interval (LI). Moreover, CYP19 gene polymorphism did not affect birth weight (BW), weaning weight (WW), 6, 9 and 12 months (YW) body weights, age at first lambing (AFL) and lambing interval (LI).