Association of single nucleotide polymorphisms in leptin (LEP) and leptin receptor (LEPR) genes with backfat thickness and daily weight gain in Ukrainian Large White pigs

Leptin (LEP) and leptin receptor (LEPR) genes play an important role in the regulation of fat deposition and other commercially important traits in pigs and this regulation is known to be breed-specific. The aim of the present study was to investigate the presence and frequency of LEP polymorphisms g.2845A > T, g.3996T > C, and LEPR polymorphisms c.232A > T, c.915C > T and c.2856C > T in Ukrainian Large White pigs, and to determine whether these polymorphisms are associated with the following traits: backfat thickness at the 10th rib, backfat thickness at the 6-7th rib, backfat thickness at sacrum and average daily weight gain. The study was conducted on 108 Ukrainian Large White purebred female pigs. Genotyping of LEP and LEPR polymorphisms was performed using RCR-RELF technique. The study demonstrated that the LEP SNP g.2845A > T was segregating in the population of Ukrainian Large Whiter pigs studied with almost equal frequencies of the alternative alleles being observed. The LEP SNP g.3996 T > C was absent in Ukrainian Large White pigs with all the animals having g.3996CC genotype. The LEPR SNP c.915C > T was segregating in the pig population studied with c.915C allele frequency dominating. Segregation was also observed for the LEPR SNP c.2856 C > T with an almost equal frequency of the alternative alleles. The LEPR SNP c.232A > T was polymorphic with the frequency of the alternative alleles c.232A and c.232T being 0.25 and 0.75 respectively. No association was established between any of the traits investigated and the LEP SNP g.2845 A > T, LEPR SNP c232A > T, and LEPR SNP c.915C > T. The LEPR SNP c.2856C > T was associated with backfat thickness at the level of 6-7th and 10th ribs with c.2856TT genotype having lower backfat thickness compared to c.2856CC and c.2856CT. The LEPR SNP c.2856C > T was also associated with average daily weight gain which was lower in animals with c.2856TT genotype. Results of the study suggest that LEPR SNP c.2856C > T can be considered as a genetic marker for subcutaneous fat deposition and average daily weight gain in Ukrainian Large White pigs. This marker can be of particular importance in breeding programmes aiming to modify the carcass structure and pigs growth rate.