Polymorphism of the MTNR1A Melatonin Receptor Gene in Goat Breeds of Northern Italy.

Simple Summary: To date, there is a lack of available data regarding Italian goat breeds other than the Sarda goat in relation to the polymorphism of the MTNR1A melatonin receptor gene, which is responsible for variations in the reproductive performance of small ruminants. The objective of this study was to detect any PCR-RFLP polymorphic sites of MTNR1A in Northern Italian goat breeds, notably known for a pronounced reproductive seasonality. Unexpectedly, no polymorphism was detected in any of the investigated goat breeds. It is hypothesized that the absence of polymorphism may be linked to the macro group of goat breeds that evolved during human migrations. Specifically, breeds of the Alpine–European strain would appear to show no polymorphism, as confirmed by our study, whereas breeds belonging to the Mediterranean–African or Asian–Middle Eastern strains do. Future investigations will be needed to confirm this hypothesis and clarify the role of MTNR1A in regulating the reproductive activity in goats. Melatonin receptor MT1, encoded by the MTNR1A gene, is the main one involved in the seasonal regulation of reproductive activity. A correlation between this gene polymorphism and reproductive performance has been demonstrated in sheep. To date, no data about MTNR1A gene polymorphism are available regarding Italian goat breeds other than the Sarda goat. This study aimed to detect any PCR-RFLP polymorphic sites of MTNR1A using MnlI and RsaI enzymes in Northern Italian goat breeds, which are characterized by a pronounced reproductive seasonality. One-hundred-eight adult female goats belonging to four different breeds were included in the study (i.e., Frisa Valtellinese, n = 29; Orobica, n = 23; Lariana, n = 29; Camosciata delle Alpi, n = 27). Blood was sampled from each goat. Genomic DNA was extracted from each sample and the main part of exon II of MTNR1A gene was amplified by PCR and digested with MnlI and RsaI enzymes. Unexpectedly, none of the fragments were found to be polymorphic. The absence of polymorphism may be linked to the macro group of goat breeds that evolved during human migrations. Breeds of the Alpine–European strain would appear to show no polymorphism, as confirmed by our study, whereas breeds belonging to the Mediterranean–African or Asian–Middle Eastern strains do. [ABSTRACT FROM AUTHOR]