Prolactin reeeptor gene polymorphism and its association with litter size in Polish Landrace

Abstract. Prolactin reeeptor gene (PRLR), which is localized on chromosome 16 in pigs, is a candidate gene marker for reproductive traits. The experiment was aimed to detect the DNA mutations in that gene and to find probable relations between the genotype and some reproductive traits in Polish Landrace pigs 207 sows and 8 boars from pedigree herd were studied. The polymorphism in PRLR gene locus was detected using PCR-RFLP method, with specific primers and restriction enzyme Alul. Two different alleles were identified: PRLR^A; PRLR^B. The frequency of PRLR^A was estimated at 0.44 and PRLR^B – 0,56. In the studied population of pigs frequencies of genotypes AA, AB and BB were 0.247, 0.386 and 0.367, respectively. The relations between PRLR genotypes and teats number on the left and right body side, total number of teats, number of piglets in the litter and the age at the first parity were analyzed. All data were transformed from the discrete scale into the quantitative one. The analysis showed the significant dependencies (P ≤ 0,01) between the number of piglets in the first litter and genotype of prolactin receptor. Significantly greater number of piglets characterized the sows carrying AA genotype.