Association of Exon 4 Region of Gpr54 Gene Polymorphisms with Litter Size Trait in Iranian Sanjabi and Ghezel Sheep Breeds by PCR –SSCP

G-protein-coupled receptor (GPR54) is one of the known gene affecting fecundity. This gene  affects  the ovulation rate and litter size performance. A total of 160 animals including Sanjabi (n=100) and Ghezel (n=60) were used to identify polymorphisms of GPR54 gene and  their influence on litter size. Genomic DNA was extracted by commercial DNA kit. The genotypic patterns were detected using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). The genotypic patterns frequencies for three detected patterns in Sanjabi sheep were 54.93, 17.59 and 17.59 percent, and for two detected patterns of Ghezel were 41.86, 58.14 percent, respectively. Significant association (P<0.05) was identified between detected genotypes with litter size in Sanjabi, but no significant association (P>0.05) was found between detected polymorphisms with litter size in Ghezel sheep. Although the  results showed that the detected polymorphisms  in this gene can be used as a marker for twinning in Sanjabi sheep but,  it may be necessary to carry out further studies with larger sample sizes to find an exact correlation between GPR54 gene variants and fecundity trait.