Effect of aryl alkyl amine-N-acetyl-transferase gene polymorphism on melatonin in non-seasonal ewes

摘要

Jugular blood was taken from 20 Awasi ewes lambing out of season during October, November and December 2016 for amplification and sequencing of Ovis aries AA-NAT gene. We also collected 40 blood samples for plasma melatonin at 3:00 PM and 9:00 PM from20 non-seasonal ewes which had had estrus during the previous Spring. Two primer amplified regions of the AA-NAT gene were compared with BLAST to confirm the gene and PCR-RFLP was used to detect polymorphisms. Melatonin in plasma was measured with an ELISA kit. Results showed a missense mutation in exon III A 1672 R that made a change in arginine to arginine C glycine and histidine to arginine & histidine and in C 1690 Y from alanine to valine and alanine. Two silent mutations (C 1676 T and A 1721 G) showed no change in amino acids. AG and GG Ovis aries AA-NAT genotypes appeared as single nucleotide polymorphisms (SNP) A 1665 R and A 1665 G. SNP A 1665 R may enhance AA-NAT, melatonin levels and reproduction. We found significant differences (P<0.05) in plasma melatonin levels between GG (31.034 ± 2.06 pg/ml) and AG (27.0715 ± 1.52 pg/ml) genotypes.