5 research outputs found
Haplotypes of the porcine peroxisome proliferator-activated receptor delta gene are associated with backfat thickness
Get PDF<p>Abstract</p> <p>Background</p> <p>Peroxisome proliferator-activated receptor delta belongs to the nuclear receptor superfamily of ligand-inducible transcription factors. It is a key regulator of lipid metabolism. The peroxisome proliferator-activated receptor delta gene (<it>PPARD</it>) has been assigned to a region on porcine chromosome 7, which harbours a quantitative trait locus for backfat. Thus, <it>PPARD </it>is considered a functional and positional candidate gene for backfat thickness. The purpose of this study was to test this candidate gene hypothesis in a cross of breeds that were highly divergent in lipid deposition characteristics.</p> <p>Results</p> <p>Screening for genetic variation in porcine <it>PPARD </it>revealed only silent mutations. Nevertheless, significant associations between <it>PPARD </it>haplotypes and backfat thickness were observed in the F2 generation of the Mangalitsa × Piétrain cross as well as a commercial German Landrace population. Haplotype 5 is associated with increased backfat in F2 Mangalitsa × Piétrain pigs, whereas haplotype 4 is associated with lower backfat thickness in the German Landrace population. Haplotype 4 and 5 carry the same alleles at all but one SNP. Interestingly, the opposite effects of <it>PPARD </it>haplotypes 4 and 5 on backfat thickness are reflected by opposite effects of these two haplotypes on PPAR-δ mRNA levels. Haplotype 4 significantly increases PPAR-δ mRNA levels, whereas haplotype 5 decreases mRNA levels of PPAR-δ.</p> <p>Conclusion</p> <p>This study provides evidence for an association between <it>PPARD </it>and backfat thickness. The association is substantiated by mRNA quantification. Further studies are required to clarify, whether the observed associations are caused by <it>PPARD </it>or are the result of linkage disequilibrium with a causal variant in a neighbouring gene.</p
