QX recombinant inbred advanced intercross lines of C. elegans

Mutation generates the heritable variation that genetic drift and natural selection shape. In classical quantitative genetic models, drift is a function of the effective population size and acts uniformly across traits, while mutation and selection act trait-specifically. We identified thousands of quantitative trait loci (QTL) influencing transcript abundance traits in a cross of two C. elegans strains; although trait-specific mutation and selection explained some of the observed pattern of QTL distribution, the pattern was better explained by trait-independent variation in the intensity of selection on linked sites. Our results suggest that traits in C. elegans exhibit different levels of variation less because of their own attributes than because of differences in the effective population sizes of the genomic regions harboring their underlying loci. RNA was measured from developmentally synchronized young adult hermaprhodites from each of 208 recombinant inbred advanced intercross lines. Strains were grown at 20 degrees C on NGM plates seeded with OP50 E. coli, following standard C. elegans procedures. Experimental methods follow those described in Capra et al., PLoS ONE 3, e4055 (2008). The genotypes of the 208 strains are detailed in Rockman and Kruglyak, PLoS Genet 5, e1000419 (2009). Each sample was cohybridized with a common pooled reference, with Cy3 and Cy5 assigned randomly to sample or reference for each experiment. Please also see 'Genotypes.txt' file available on the Series record for strain/genotype details.