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Genotyping of rams based on melatonin receptor 1A gene polymorphisms: a tool in sire selection?

Victoria Peña-Delgado, Agustí Noya, Melissa Carvajal-Serna, Francisco Canto, María Carmen Sánchez, Eva Letosa, Antonio Vicente, Ignacio Morato, Ángel Macías, Jose Alfonso Abecia, Adriana Casao , Rosaura Pérez-Pe

Abstract

Context. Several polymorphisms in the MTNR1A (melatonin receptor 1A) gene have been related to reproductive performance in ovine. Aims. To investigate the effect of the RsaI and MnlI polymorphisms on ram seminal quality. Methods. Eighteen Rasa Aragonesa rams were genotyped for the RsaI (C/C, C/T, T/T) and MnlI (G/G, G/A, A/A) allelic variants of the MTNR1A gene. Individual ejaculates were analysed once a month throughout the whole year. Sperm motility, morphology, membrane integrity, levels of reactive oxygen species (ROS), phosphatidylserine (PS) inversion, DNA fragmentation and capacitation status were assessed. The effect of the season and polymorphisms on seminal quality was evaluated by mixed ANOVA. Key results. Both polymorphisms had an effect on membrane integrity and viable spermatozoa with low levels of ROS and without PS translocation, and RsaI also on motile and DNA-intact spermatozoa. An interaction between both polymorphisms was found, pointing to a negative effect on seminal quality of carrying the T or A allele in homozygosity. Differences were higher in the reproductive than in the non-reproductive season. Conclusions. Mutations substituting C by T and G by A at RsaI and MnlI polymorphic sites respectively in the MTNR1A gene in rams could decrease the seminal quality. Implications. Genotyping of rams based on melatonin receptor 1A could be a powerful tool in sire selection.

RD23235  Accepted 23 April 2024

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