Two polymorphisms of the porcine prolactin receptor (PRLR) gene were previously related to litter size by several authors; however, the magnitude and direction of such effects varied depending on the population analyzed. We have sequenced the complete coding region of the porcine PRLR gene and found 6 nonconservative SNP: C1217T (Leu/Pro406), C1283A (Asp/Ala 428), G1439A (Lys/Arg480), T1528A (Met/Leu510), G1600A (Gly/Ser534), and G1789A (Gly/Ser597), within exon 10 of the gene, which encodes the entire intracytoplasmic domain of the protein. Eight haplotypes were found and were segregating at different frequencies in 6 porcine breeds. The effects of each individual SNP and haplotype were evaluated in an Iberian x Meishan F2 population using a univariate mixed-inheritance animal model. Significant effects on the number of corpora lutea were found for PRLR haplotypes (P < 0.012), confirming the previously reported associations of PRLR in this process and highlighting the importance of performing analysis of haplotypes rather than of individual SNP. Suggestive effects or tendencies were found for heart rate at birth (P < 0.10), rectal temperature (P < 0.05), and oxygen saturation (P < 0.10) 1 h after birth, and time to first suckle (P < 0.10). We found greater than expected levels of amino acid variability within the intracellular domain of the porcine PRLR, which have been associated with differences in the number of corpus lutea of sows and the preweaning survivability of piglets. ©2006 American Society of Animal Science. All rights reserved.
- Pig prolactin receptor
- Piglet survival