Polymorphism of the Melatonin Receptor Genes and its Relationship with Seasonal Reproduction in the Gulin Ma Goat Breed

Abstract

Melatonin is thought to be the main molecule that transmits the signal of seasonal change to the neuroendocrine system in seasonal breeding species. Melatonin exerts its effects through specific melatonin receptors, MTNR1A and MTNR1B. In the present study, six native goat breeds in China and one introduced goat breed were analysed to investigate the relationship between the genetic polymorphism of receptor genes and seasonal reproduction. Sequencing results showed that there were five polymorphic mutations in the MTNR1A gene and two in the MTNR1B gene. In the MTNR1A gene, genotypes AA, AB and BB for 424C>T and genotypes CC, CD and DD for 589C>A were observed in these goat breeds. In all six native goat breeds, only genotype AA was detected. In the MTNR1B gene, genotypes EE, EF and FF for 1179G>A and genotypes GG, GH and HH for 1529A>G were detected. However, in Gulin Ma goats, the genotypes EE and HH were not found. Moreover, the base of G at position 1179 and A at position 1529 were linked (By Arlequin ver 3.1, Zoological Institute, Berne, Switzerland, http://cmpg.unibe.ch/software/arlequin3,D' = 0.7496, r(2) = 0.4421, χ(2) = 489.8679, p = 0.000). Among these mutations, no amino acid change was found in MTNR1A, while both of the mutations in MTNR1B gene caused amino acid changes of R222H and S339G, respectively. The structural analysis showed that the R222H mutation occurred in the first amino acid residue of the third cytoplasmic loop, and the S339G mutation was located in the carboxyl terminus of the protein. In terms of seasonal breeding, all the genotypes we detected showed a similar kidding frequency distribution trend with a higher frequency in May-August than in January-April and in September-December. This suggests that the relationship between the polymorphisms in the MTNR1A and MTNR1B genes and seasonal breeding could not be established.

Association study and expression analysis of MTNR1A as a candidate gene for body measurement and meat quality traits in Qinchuan cattle

“…We postulate that this mutation may change the amino acid sequence of a protein, which in turn may affect the level of translation efficiency, thereby altering the function of melatonin. Previous studies have found that a missense mutation of the MNTR1A gene significantly altered the cAMP signal transduction pathway (Trecherel et al, 2010;Lai et al, 2013). In our study, expression analysis showed that individuals with the mutant heterozygotic genotype SNP1/2/4-AG-GA-CT had significantly higher levels of MTNR1A mRNA expression than wild homozygotic genotype SNP1/2/4-AA-GG-CC.…”

“…Although the SNP1 g.A455G and SNP4 g.C635T do not change the amino acid sequence, some reports confirmed that the synonymous SNPs can affect in vivo protein folding and consequently its function as well as the gene expression and phenotype Sauna et al, 2007). Synonymous mutations in the MNTR1A gene have been found to be closely associated with reproduction traits in pigs, sheep, and goats (Ramírez et al, 2009;Mura et al, 2010;Lai et al, 2013). The SNP2 g.G489A is a missense mutation.…”

“…In mammals, MTNR1A and MTNR1B have been cloned in many species and it has been found that MTNR1A has a unique capacity for high-affinity binding to melatonin and that it mediates numerous physiological functions (Reppert et al, 1996;Lai et al, 2013;Yang et al, 2014aYang et al, , 2014b. Based on this background, it is rational to hypothesize that the MTNR1A gene may be correlated with body measurement traits (BMTs) and meat quality traits (MQTs).…”

Melatonin receptor 1A gene RsaI and inhibin alpha subunit gene HaeII polymorphisms in Honamli and Hair goat breeds reared in Western Mediterranean region of Turkey

“…In turn, seasonal reproductive activity for livestock such as goats, sheep, and buffalo is significantly influenced by melatonin (24). On the other hand, MTNR1A is thought to be the main receptor involved in the regulation of seasonal reproductive activities in mammals (11).…”

No polymorphism of melatonin receptor 1A (MTNR1A) gene was found in Markhoz goat

“…The primers were used to amplify the interested regions according to Lai et al . (). The primers were manufactured by CinnaGen Co., Ltd.…”