In PLoS Biology this week, investigators at Stanford and their colleagues demonstrate that "a simple genetic architecture underlies morphological variation in dogs." By creating a high-density map of genetic variation through genotyping 915 dogs with various phenotypes across 60,968 SNPs, the team identified "51 regions of the dog genome associated with phenotypic variation among breeds in 57 traits." The authors write that "across dog breeds, a small number of quantitative trait loci explain the majority of phenotypic variation for most of the traits we studied," and suggest that "many genomic regions show signatures of recent selection." See GenomeWeb Daily News coverage of this study, here.
In a PLoS Genetics paper, David Speca at the University of California, San Francisco, and his colleagues describe the "conserved role of unc-79 in ethanol responses in Lightweight (Lwt) mutant mice." Speca et al. performed mutagenesis screens for mice with enhance locomotor activity and found that the Lwt allele disrupts the homolog of C. elegans unc-79. Lwt heterozygotes are "dramatically hypersensitive to acute ethanol exposure," the authors write, adding that they "exhibit increased food consumption yet have a leaner body composition ... [and] voluntarily consume more ethanol than wild-type littermates." The authors suggest that their work suggests a "conserved pathway that might influence alcohol-related behaviors in humans."
Researchers at the Broad Institute and their colleagues report a method for meta-analysis gene-set enrichment of variant associations, which they've dubbed "MAGENTA." Their method "tests whether sets of functionally related genes are enriched for associations with a polygenic disease or trait," the authors write, adding that the program "was specifically designed to exploit the statistical power of large genome-wide association study meta-analyses whose individual genotypes are not available." Using MAGENTA, the team found "no significant enrichment of associations" to type 2 diabetes or glycemic traits tested in a recent GWAS. The authors suggest "that common variants affecting nuclear-encoded mitochondrial genes have at most a small genetic contribution to T2D susceptibility."
And in PLoS One this week, researchers at the Quest Diagnostics Nichols Institute and their colleagues in Texas show that "the JAK2 Δexon14 splice variant ... is common in patients with MPNs [myeloproliferative neoplasms]" and most common in MPN patients without the V617F mutation, which is "missed if DNA rather than RNA is used for testing," the authors write.