Marek Kmieć

Associations between the prolactin receptor gene polymorphism and reproductive traits of boars

The prolactin receptor gene (PRLR), located on chromosome 16 in pigs, is a candidate gene for reproductive traits. The experiment was aimed to detect the DNA mutations in this gene and to find probable relations between the genotype and some reproductive traits in boars. The polymorphism in thePRLR gene was identified by PCR-RFLP method using specific primers and the restriction enzymeAluI. In total 229 boars of various breeds were genotyped. The frequency of allele A was estimated at 0.62 and allele B at 0.38. Genotype AA was found at a frequency of 0.45, AB at 0.35 and BB at 0.20. We found associations betweenPRLR genotype and ejaculate volume, sperm concentration, percentage of live sperm, and number of live sperm in the ejaculate (P < 0.01).

Association between leptin gene polymorphisms and growth traits in Limousin cattle

A total of 129 Limousin calves were used to investigate how leptin gene polymorphisms affect growth traits, such as body weight, average daily gain, wither height, sacrum height and chest girth in beef cattle. Two single nucleotide polymorphisms (SNPs) were genotyped, including the Sau3AI polymorphism in intron 2 and the A59V polymorphism in exon 3. The genotype and allele frequencies for each SNP and the haplotype frequencies for both SNPs were estimated in the studied herd. Statistical analysis revealed that the A59V polymorphism significantly affected the body weight at 210 days of age (P ≤ 0.01) and the average daily gain between 3 and 210 days of age (P ≤ 0.05) with T as a desirable allele. No associations were observed between the Sau3AI polymorphism and the growth traits mentioned above. However, the average daily gain between 3 and 210 days of age was significantly higher in the CT/CT haplotype animals compared with the CC/CC and CC/CT individuals. These results indicated that selection for the A59V TT animals might contribute to an improved body weight in Limousin cattle.

The effect of calpastatin polymorphism and its interaction with RYR1 genotypes on carcass and meat quality of crossbred pigs

The aim of the study was to establish the relationship between a calpastatin gene (CAST) polymorphism, the ryanodine receptor gene (RYR1) polymorphism and carcass/meat quality traits in crossbred pigs. No significant differences in the analyzed pigs were found between genotypes CC and CT at the locus RYR1 and CD and DD at the locus CAST/MspI in terms of carcass and meat quality. However, a significant association of the CAST/ApaLI polymorphism with carcass quality and meat marbling were observed. The carcasses of AB pigs had significantly higher carcass percentage of lean meat, thinner backfat and thicker muscle, as well as lower meat marbling, as compared with the BB pigs. Furthermore, interactions CAST/MspI × RYR1 and CAST/ApaLI × RYR1 were found significant in relation to all the studied carcass traits. The results presented here imply that the CAST gene recognized with ApaLI may be considered as important in terms of the way it affects porcine carcass quality traits. Moreover, the research has revealed a relationship between CAST and RYR1 genotypes as regards formation of carcass traits in pigs. Follow-up studies, however, should be carried out on larger populations representing all possible CAST genotypes.;

STAT5A/AvaI RESTRICTION POLYMORPHISM IN COWS OF POLISH RED-AND-WHITE VARIETY OF HOLSTEIN FRIESIAN BREED

The study on polymorphism within the STAT5A gene (transition C6853T) was conducted using the PCR-RFLP method and AvaI restrictase. The study covered a herd of 723 cows of the Polish Red-and-White variety of Holstein Friesian breed, kept for dairy purposes in the Opole region, Poland. Two alleles (C and T) of the analyzed STAT5A polymorphism were found in the studied herd. The alleles determined the occurrence of two genotypes: CC and CT. The homozygous TT genotype was not found. The STAT5A/AvaI allele frequencies were as follows: C—88.31% and T—11.69%, whereas the genotype frequencies were 76.6% for CC and 23.4% for CT. The analysis of associations between the STAT5A/AvaI polymorphism and milk utility traits considered in the study showed that these traits were different in animals with different STAT5A/AvaI genotypes.