BackgroundIndependent studies have shown that several single nucleotide polymorphisms (SNP) in the human FTO (fat mass and obesity associated) gene are associated with obesity. SNP have also been identified in the pig FTO gene, among which some are associated with selected fat-deposition traits in F2 crosses and commercial populations. In this study, using both commercial pig populations and an experimental Meishan × Pietrain F2 population, we have investigated the association between one FTO SNP and several growth and carcass traits. Association analyses were performed with the FTO polymorphism either alone or in combination with polymorphisms in flanking loci.MethodsSNP (FM244720:g.400C>G) in exon 3 of porcine FTO was genotyped by PCR-RFLP and tested for associations with some growth, carcass and fat-related traits. Proportions of genetic variance of four pig chromosome 6 genes (FTO, RYR1, LIPE and TGFB1) on selected traits were evaluated using single- and multi-locus models.ResultsLinkage analysis placed FTO on the p arm of pig chromosome 6, approximately 22 cM from RYR1. In the commercial populations, allele C of the FTO SNP was significantly associated with back fat depth and allele G with muscling traits. In the Meishan × Pietrain F2 pigs, heterozygotes with allele C from the Pietrain sows and allele G from the Meishan boar were more significantly associated with fat-related traits compared to homozygotes with allele G from the Pietrain and allele G from the Meishan breed. In single- and multi-locus models, genes RYR1, TGFB1 and FTO showed high associations. The contribution in genetic variance from the polymorphism in the FTO gene was highest for back fat depth, meat area on the musculus longissimus lumborum et thoracis tissues and metabolite glucose-6-phosphate dehydrogenase.ConclusionsOur results show that in pig, FTO influences back fat depth in the commercial populations, while in the Meishan × Pietrain F2 pigs with a CG genotype, heterosis occurs for several fat-related traits.

ABSTRACT:Collie eye anomaly (CEA) is an inherited eye disease affecting development of the choroids and sclera segregating in several, mostly herding breeds of dog. Phenotypic development of the disease varies greatly in the affected animals. Genetic control of its clinical variation is unknown so far. Affected dogs share a 7.8 kb deletion in intron 4 of the NHEJ1 gene. We report here population studies of 379 dogs (Australian Shepherd, Border Collie, Rough Collie, Smooth Collie, Shetland Sheep Dog, and Nova Scotia Duck Tolling Retriever) from breeders in the Czech Republic. A simple PCR method using a Piko TM Thermal Cycler and unclotted blood samples was employed for the analysis of the NHEJ1 gene. No isolation of DNA from blood samples before PCR was needed. The method is time-saving and gives excellent results. Frequencies of the disease allele in each breed were calculated (0. 045, 0.194, 0.797, 0.367, 0.429 and 0.244, respectively). An improvement of genetic health of the breeds on the basis of allele frequencies is discussed.

Progressive rod-cone degeneration (PRCD) is a late onset autosomal photoreceptor degeneration found in canines. PRCD in canines is homologous to one form of retinitis pigmentosa (RP) found in humans and displays phenotypic similarity as well as having the identical causative mutation. The PRCD gene was mapped to the centromeric region of canine chromosome 9 (CFA9). We report here a population study of 699 dogs of the following breeds and the following frequencies of the disease-causing mutation: American Cocker Spaniel (0.09), English Cocker Spaniel (0.34), English Springer Spaniel (0.00), Welsh Springer Spaniel (0