PCR-SSCP Analysis On Intron Ⅰ And Ⅱ Of Prolactin Receptor Gene In Goats

Jining Grey goats that has significant characteristics of high prolificacy and nonseasonal ovulatory activity is an excellent local goats breed in P.R. China. The kidding percentage averaged 293.65 percent in Jining Grey goatss. Prolactin receptor (PRLR) gene which controls the fecundity of Belclare and Cambridge ewes was studied as a candidate gene on the prolificacy of Jining Grey goats. According to the sequence of ovine PRLR gene, two primer pairs were designed to detect single nucleotide polymorphism of intron I of PRLR gene in both high fecundity goats breed (Jining Grey goats) and low fecundity goats breeds (Boer goats, Wendeng dairy goats, Liaoning Cashmere goats, Beijing native goats) by PCR-SSCP. The products amplified by primer 1 had polymorphism. Five genotypes (AA, AH, AK, HH and HK) were detected in Jining Grey goats, and two genotypes (AA and AK)in other four goats breeds.The sequencing results indicated that there was one single nucleotide mutation (C~119→T~119) at intron i of PRLR gene in Jining Grey goats.. Frequencies of A, H and K alleles were 0.853,0.0759, and 0.0714 in Jining Grey goats, respectly. The PRLR genotype distributions were high significantly different (P<0.01) between Jining Grey goats and Boer, Wendeng dairy goats, Liaoning Cashmere goats. The ewes with genotype AA had 0.6 (P<0.05) kids more than those with others genotypes in Jining Grey goats. The products amplified by primer 2 had polymorphism. Three genotypes (CC, CD, and DD) were detected in Boer goats, and two genotypes (CC and CD)in other four goats breeds.The sequencing results showed that there were two nucleotide mutations (G~35→A~35, and A~86→G~86) at intron II of PRLR gene in goats. Frequencies of C and D alleles were 0.9375 and 0.0625 in Jining Grey goats, respectly. The PRLR genotype distributions were high significantly different (P<0.01) between Jining Grey goats and Boer goats, Wendeng dairy goats, Liaoning Cashmere goats. The femails with genotype CC had 0.66 (P<0.05) kids more than those with genotype CD Jining Grey goats.These results implied that PRLR gene is associated with a major gene influencing the prolificacy of Jining Grey goats. In view of our results, marker-assisted selection using PRLR gene is warranted to increase litter size in goats and will be of considerable economic value to grey kidskin and mutton producers.