Polymorphisms of the melatonin receptor 1A (MTNR1A) gene affect sexual performance of Rasa Aragonesa rams without changing their social dominance

Abstract

The aim of this study was to investigate whether a specific genotype of the MTNR1A gene influences social dominance and reproductive performance in rams. Thirty-one rams were genotyped for Rsal and Mnll polymorphism of the gene: CC (n = 19), CT (n = 5), and TT (n = 7), and GG (n = 20), GA (n = 6), or AA (n = 5), respectively. Social behavior was recorded by direct observations, and rams were tested in individual serving-capacity tests. The genotypes did not differ in the numbers of aggressions that they performed or received, and their active and passive behaviors were similar. For the Rsal and Mnll polymorphism, TT and GG rams were responsible for 54% and 56% of the total number of recorded sexual events (P < 0.05), respectively. Results of this study confirm that the best sexual performance of rams was among those that carried certain genotypes of the MTNR1A gene, but it was not correlated with differences in social dominance.

Polymorphisms of the melatonin receptor 1A (MTNR1A) gene do not affect sexual activity, plasma testosterone concentrations or testicular characteristics of 8-month-old ram-lambs born in autumn

“…At the pre-pubertal stage, a ram's social rank can affect how well it reproduces in adulthood, although testosterone serum levels and semen output are not correlated with social rank (Ungerfeld and Lacuesta 2010). Our earlier research showed that the social hierarchy in the ram flock was not related to the increase in the rams' sexual performance in the spring that carried particular genotypes of the MTNR1A gene (Abecia et al 2022). Rams that carried the TT genotype at position g.17355458 C>T, and the GG genotype at position g.17355452G>A performed sexually better in the spring, but their social status was not significantly different from that of the rams that carried the other genotypes.…”

Multifaceted Interplay among Social Dominance, Body Condition, Appetitive and Consummatory Sexual Behaviors, and Semen Quality in Dorper Rams during Out-Of-Season and Transition Periods

“…Recently, the possible role of specific genotypes of the melatonin receptor 1A (i.e., MTNR1A ) gene in social dominance and reproductive success was tested in rams. Although some males carrying certain genotypes of the MTNR1A gene displayed the best sexual performance, such superiority was exerted in a non-social hierarchized fashion [ 45 ].…”