Polymorphisms of the osteopontin gene and level of its expression in the reproductive tract of sows / Polimorfizm w genie osteopontyny i poziom jej ekspresji w układzie rozrodczym loch

The aim of the study was to find osteopontin gene (OPN) polymorphisms as potential mutations affecting the expression level of genes in the ovaries, uterus and oviduct of sows. The material consisted of 71 F1 sows (Polish Large White × Polish Landrace). In the first stage several polymorphisms in the promoter region, intron 6, exon 6 and 7 of the OPN gene were found. The parameters estimated were the frequency of alleles and genotypes, observed heterozygosity and gene diversity, PIC, and chi2 factors. Chi2 values allow for assessment of genetic equilibrium in the population. Thus, the loci OPNp3-4 and OPNe6-1 were in genetic disequilibrium while locus OPNe6-Knoll showed genetic equilibrium. Also real-time PCR analysis to determine the expression dynamics of the OPN gene in examined tissues was performed in relation to “housekeeping” genes. A comparison was made for relative expression in different tissues and different mutations. The highest expression pattern was observed in the oviduct. Based on the novel polymorphisms a significant correlation between the OPN genotype and OPN expression (mRNA) level in the ovary, oviduct, uterine body and uterine horn was observed. In the second stage, the levels of expression of the OPN gene in individual tissues, traits of reproductive performance and reproductive tract traits of sows were also compared. The expression levels in the uterine body and oviduct were related to the age of mating, cervical length, litter weight at birth, number of active nipples, age at slaughter and body weight at mating.