Conference lecture and academic presentation » Poster
Identification of a novel allele of peroxisome proliferator-activated receptor gamma (PPARgamma) and its association with resistance to Aeromonas salmonicida in Atlantic salmon
The 10th International Symposium on Genetics in Aquaculture (ISGA X); BAngkok, Thailand, 2009-06-21–2009-06-28
Bacterial and viral diseases are major problems in farmed Atlantic salmon, but may be challenged through selective breeding. One strategy for selecting robust animals for breeding is through the identification of the underlying genetic variation that correlates with susceptibility to the disease. Peroxisome proliferator-activated receptor gamma (PPARG) is a lipid-sensing transcription factor primarily known for modulating energy metabolism, lipid storage, and transport. More recently, a role of the receptor in inflammation and wound healing has emerged. Here we report a novel allele of PPARG, pparg-2, in Atlantic salmon. Pparg-2 has 60 additional nucleotides compared to the previously reported allele, pparg-1, and encodes two copies of the almost perfect decapeptide motif, HSPDR(S/N)HS(F/C/Y)N. Whereas the previously described pparg-1 has six copies of the same motif, eight copies are present in the pparg-2 allele. Here, we studied the effect of pparg-1 and pparg-2 on survival after challenge with a highly virulent bacteria, Aeromonas salmonicida, causing furunculosis in Atlantic salmon, and the virus causing infectious salmon anemia (ISA), respectively, in the breeding population of AquaGen, year class 1999. The allele frequency of pparg-2 was 13%, displayed Mendelian heritance and was in Hardy-Weinberg-equilibrium in the population. For furunculosis, a TDT test revealed significant association between ppar alleles and resistance (P < 0.01).For ISA, no correlation was found. We conclude that pparg-2 is in linkage disequilibrium (LD) with, or identical to, the causative mutation. This is the first report showing an association between pparg alleles and a possible protective role in mediating immune response in fish.