摘要

mRNA expression and DNA polymorphism of prolactin receptor (PRLR) gene were investigated and used to study their effects on litter size in goats. Real-time polymerase chain reaction (PCR) analysis revealed that PRLR mRNA levels in pituitary and endometrium of prolific Lezhi black goats were 39.0-fold and 29.9-fold higher than those in non-prolific Tibetan goats (P < 0.05), but there was no difference in ovary and liver between the two breeds. To further explore the possible association between variations in PRLR gene with litter size in Lezhi black goat, mutation screening of exon 10 of PRLR was performed by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). In P2 locus, the four genotypes AA, AB, AC, and AD had the genotypic frequencies of 0.136, 0.110, 0.162, and 0.594, respectively, but no polymorphism was detected in P1 locus. There were four mutations at C89T, A94C, C146G, and G157C of this fragment in all of the four genotypes, which led to a missense mutation Pro to Leu, Asn to His, Ala to Gly, and Ala to Pro, respectively. In addition, a mutation of C61T in genotype AA, A175G in genotype AD, T24C and C96T in genotype CD were detected. The Lezhi black does with genotype AD had 0.35 (P < 0.05) more kids than those with genotype AB, but there was no significant difference among other genotypes. It is concluded that PRLR gene expression and mutations in exon 10 of PRLR gene may be associated with the reproductive effects of the Lezhi black goat.

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