Polymorphisms in the melatonin receptor gene promoter and their associations with fertility characteristics in buffalo herd in Eastern Amazon

Abstract

ABSTRACT. Buffalo production is spreading globally because of its economic advantage. Then, it has become necessary to improve the reproductive and productive efficiency of these animals, as well as to look for genetic factors that increase this efficiency. The objectives of this study were to characterize the promoter region of the melatonin 1A receptor gene (MTRN1A), to detect possible SNPs and associate them with fertility characteristics, and identify binding sites of transcription factors involved in the regulation of genetic expression 2 E.M. Barbosa et al. Genetics and Molecular Research 16 (2): gmr16029610 in buffaloes in the Amazon. The conventional PCR method was carried out using the two primers designed from the reference sequence deposited in the GenBank AY52466.1. The products of the PCRs were purified, sequenced, and subsequently edited and aligned. Twenty-six SNPs were found, where 73% presented allele frequencies of wild nucleotides above 0.5, and 73% presented deviations from the HardyWeinberg equilibrium (P < 0.05) and F IS varying between 0.06 and 1.00, characterizing high degrees of inbreeding within the population. A block of ACAA deletion (position -1483) was observed in 25% of samples. The associations between these SNPs and reproductive characteristics were observed for calving interval and 5 SNPs: -1289, -1139, -911, -724, and -656 (P < 0.05), and three other SNPs: -1395, -724, and -94 (P < 0.05) were associated significantly with age at first calving, and were not associated with calving concentration. The promoter region was characterized by the different types of binding factors, where only 11 sites are significantly strong enough for transcription factor bindings. The ACAA deletion also exhibited a strong association with transcription factors. As a result, it would be necessary to test the SNPs above with other reproductive characteristics of economic relevance to approve the gene as a strong candidate for the selection of buffaloes in the Amazon.

Genetic polymorphism in melatonin receptor 1A and arylalkylamine N-acetyltransferase and its impact on seasonal reproduction in Egyptian sheep breeds

“…Exon 2 of the MTNR1A gene is known to be highly polymorphic, and one of these polymorphisms involves a restriction site for the RsaI enzyme, 606 C > T (Saxena et al, 2015a). The AA-NAT gene is considered an ideal gene to investigate possi- ble SNPs that could clarify the large individual variations in serum melatonin levels and may aid in controlling seasonal reproductive activity (Klein, 2007;Barclay et al, 2010). The results of PCR RFLP revealed three genotypes (CC, CT and TT) for exon 2 of the MTNR1A gene and three (GG, GA and AA) for exon 3 of the AA-NAT gene, and two alleles were detected for each gene in all analyzed breeds, which emphasizes that selection has not eliminated any of the alternative forms of the MTNR1A gene (Notter and Cockett, 2005).…”