Abstracts (first author)
A novel functional polymorphism in the Fatty Acid Desaturase 2 gene (FADS2): possible role in basal metabolic ratePDF
As membrane components, polyunsaturated fatty acids (PUFAs) play an important role in cellular processes and have been shown to be associated with basal metabolic rate (BMR). While the link between BMR and membrane lipid composition is clear on an interspecific level, the underlying mechanism linking them on an intraspecific level is not well understood. Probably one reason for this is that variation of a physiological trait like BMR is much narrower within a species than between organisms from two different species, and in turn the mechanisms explaining any observed variation could be subtler. In this circumstance, a much stronger methodology for studying BMR should be found in artificial selection experiments which manipulate the frequencies of genes directly related to the trait under study. Here we describe a new polymorphism in the fatty acid desaturase (Fads2) gene for Δ-6 desaturase (D6D), a key enzyme for PUFA synthesis, in 120 males from two genetic lines of outbred Swiss Webster laboratory mice (Mus musculus) selectively bred for 32 generations (F32) towards low and high BMR. For controlling the force of genetic drift, we also used 78 mice of generation 22 (F22). For the same reason, we analyzed 36 mice from three unselected lines of mice maintained in a separate, concurrent selection experiment in generation 16 (F16). The aim of this study was to verify a possible association between Fads2 genotypes and BMR. We found significant correlation between Fads2 variants and BMR within selected, as well as unselected lines of mice. We also used a FST outlier test to asses the effect of selection on the variation between L-BMR and H-BMR lines of mice at the Fads2 gene, using the Fads2 gene, together with data from the 11 microsatellite loci. Taken together, these results suggest that Fads2 is expected to become a major focus of membrane, metabolic rate and human metabolic syndrome research.