Association of Polymorphisms at PRLR Gene Loci with Litter Size in Haimen Goat

Abstract

Haimen goat is an exclusive and relatively rare indigenous Chinese goat breed that can produce high quality Brush Hair specialized in making valuable writing brush. To enlarge quickly the population size of Haimen goat, certain genetic markers that can improve litter size are needed in the breeding process. To search for suitable genetic markers related to litter size, the polymorphisms at the PRLR gene loci were investigated by PCR and single-strand conformation polymorphisms (SSCP) in Haimen goat, and their associations with litter size were analyzed by genetic tools. Results showed that two alleles are found on PRLR gene Intron 1, with gene frequencies was 0.59 and 0.41, respectively; the heterozygosity (He), effective allele number (Ne) and polymorphic information content (PIC) in Haimen Goat based on Intron 1 was 0.4838, 1.9372 and 0.3668, respectively; Two alleles were found on PRLR gene Intron 2, and gene frequencies was 0.79 and 0.21, respectively. He, Ne and PIC in Haimen Goat on Intron 2 was 0.3318, 1.4966 and 0.2768, respectively. The genetic variation indicated that the Haimen goat population was moderately polymorphic. The least square analysis and multicomparison of PRLR gene loci and litter size demonstrated that the SNP (A35G) on Intron 2 of the PRLR gene affected extremely significantly on litter size, with CC as the advantageous genotype for the trait of litter size; while the SNP (T95C) on Intron 1 had no significantly effect on litter size in Haimen goat. The results would provide some evidence for SNP (A35G) on Intron 2 of the PRLR gene as a candidate marker for the trait of litter size in goat.