Controllo genetico della stagionalità riproduttiva in ovini di razze autoctone

Genetic control of reproductive seasonality in native sheep Reproductive physiology in sheep can change with latitudes. It’s normally characterized by seasonality, and is regulated by photoperiod’s exposure. The aim of this study was to investigate the GPR54, MTNR1a and KiSS1 genes polymorphisms in Sardinian and Slovenian local breeds, in order to determine if there is an association with reproductive seasonality. The PCR-SSCP analysis was carried out on 250, 130, and 106 bp fragment, respectively from GPR54 exons 1 and 2 and KiSS1 exon 1, while for the 824 bp fragment from MTNR1A gene exon 2 was also added RFLP analysis, using MnlI and Rsa1 endonucleases. Some polymorphic sites were found: G1035A at the Kiss1 gene exon 1 leading to GG (75,7 %), GA (21,3 %) and AA (3 %) genotypes; C606T and G612A at the MTNR1A exon 2, leading to genotypes CC (42,5 %), CT (31 %) and TT (26,5 %), and GG (51,5 %), GA (34,75%) and AA (13,75 %), respectively. These two last polymorphisms showed to influence the reproductive recovery in Sarda breed. No polymorphism was found in the exon 1 and 2 of the GPR54 gene. Statistical analysis showed no correlation between genotypes and reproductive seasonality in Slovenian breed sheep. The effect of the gene genotypes, in Slovenian s sheeps, maybe was masked by management e of males put inside the group during decreasing of photoperiod, therefore already favorable at the beginning of the reproductive activity. The low frequency of genotypes found for KISS1 and GPR54 genes does not allow us to highlight possible influences of these mutations on reproductive activity.