Analysis of ESR and RBP polymorphisms in Black Slavonian sows: preliminary results

Black Slavonian pig belongs to the breeds of medium fertility with relatively high variation in litter size, denoting that it could be included in selection using molecular genetics. Estrogen receptor gene (ESR) and retinol binding protein 4 (RBP4) are candidate gene markers for sows’ reproductive traits. The aim of this preliminary study was to investigate frequencies of different ESR-PvuII and RBP4-MspI genotypes in fourteen Black Slavonian sows, as well as their reproductive traits. Sows were genotyped with PCR-RFLP method. Allele and genotype frequencies were calculated and Hardy-Weinberg equilibrium was tested using χ2-test. Litter size differences between sows of different genotypes were analyzed with analysis of variance. Three ESR-PvuII genotypes were detected with relative frequencies AA (0.54), AB (0.38) and BB (0.08), while the gene relative frequency was 0.73 for allele A and 0.27 for allele B. In the case of RBP4- MspI those values were: AA (0.54), AB (0.23) and BB (0.23), while allele frequencies were 0.65 for A and 0.35 for B allele. Analyzed genes were in accordance with Hardy-Weinberg equilibrium. There were no statistically significant differences detected between genotypes for any of the studied trait (P > 0.05). Further research on a larger sample size is needed for more conclusive evaluation of the possible correlation between ESR-PvuII and RBP4-MspI polymorphisms and reproductive parameters in Black Slavonian sows.