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

Prolactin receptor gene (PRLR), which is localized on chromosome 16 in pigs , is a candidate gene marker for reproductive traits, The experiment was ai med 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 a nd restriction enzyme AluI. Two different alleles were identified: PRLRA; P RLRB. The frequency of PRLRA was estimated at 0.44 and PRLRB - 0,56. In the studied population of pigs frequencies of genotypes AA AB arid BB were 0.2 47, 0.386 and 0.367, respectively. The relations between PRLR genotype and teats number on the left and right body side, total number of teats, number of piglets in the first litter and the age at the first parity were analyz ed. All data were transformed from the discrete scale into the quantitative one. The analysis showed the significant dependencies (P less than or equa l to 0,01) between the number of piglets in the first litter and the genoty pe of prolactin receptor. Significantly greater number of piglets character ized the sows carrying AA genotype.