Abstract：The gonadotropin releasing hormone receptor (GnRHR) gene was studied as a candidate gene for the high prolificacy of Jining grey goat(Caprar hircus). Eight pairs of primers were designed to detect single nucleotide polymorphisms of exon 1, exon 2 and exon 3 of GnRHR gene in high fecundity breed(Jining grey goat) and low fecundity breeds(Angora, Boer and Inner Mongolia Cashmere goats) by PCR-SSCP. Only the products amplified by primer P4 displayed polymorphisms. For primer P4, three genotypes (AA, AB and BB) were detected in Jining grey, Boer and Inner Mongolia Cashmere goats, only AA and AB genotypes were in Angora goats. Sequencing revealed one mutation (757G→A) of exon 1 in genotype BB compared with genotype AA, which did not cause amino acid changes. In Jining Grey goats, frequency of AA, AB and BB genotypes was 0.623, 0.300 and 0.077, respectively. The Jining grey with genotype BB had 0.69(P < 0.05) or 0.82(P < 0.05) kids, more than those with AB or AA, respectively. The difference of the least squares means for litter size between AA and AB was nonsignificant (P > 0.05) in Jining grey goat.
