Indian Journal of Animal Research

The seasonality of sheep reproduction is a major limiting factor in round the year lamb production under temperate climate. The objective of this study was to analyse allelic variants of exon II of melatonin receptor (MTNR1A) gene in Merino cross ewes by phylogenetic analysis. The genotypes of the MTNR1A were determined by PCR-RFLP. Genomic DNA was extracted from 49 Merino cross ewes, PCR reaction was carried out and PCR products were digested by the Mnl1 restriction enzyme and placed into M/M, M/m or m/m genotypes. Sequencing of the representative samples showing different RFLP patterens were got done both in forward as well as reverse direction. The obtained nucleotide sequences of different alleles of exon II fragment of the gene were analysed to generate phylogenetic relationship, the homology (percentage similarity) and the relative distance (divergence) with sheep (Ace. No's U14109, AF045219), goat (Ace. No AF419334), cattle (Ace. No EU716174), buffalo (Ace. No GU817415) and human (Ace. No AB029933). The results confirmed that the diversity in the amplified fragment is in consonance with the phylogenty of species. This study also provided evidence that Merino cross have variability in MTNRlA locus. Therefore, this locus can be used as a marker for the reproduction trait in selection programs.