Seeing traits, close-up

For the first time, researchers have discovered the molecular basis of a quantitative trait at the level of individual nucleotides. The report, appearing in the December issue of Nature Genetics, reveals that even the tiniest changes among a few genes can profoundly affect traits. The authors also describe an approach that can be used to characterize any trait in yeast -- and, potentially, higher organisms, they suggest.

In the current study, Adam Deutschbauer, now a postdoctoral fellow at the University of California, Berkeley, and Ronald Davis at Stanford University in California, focused on characterizing genes responsible for yeast sporulation efficiency, a measure of the rate at which yeast undergo asexual reproduction and develop spores. Their approach revealed three genes responsible for the trait, two of which had never before been implicated in sporulation. Furthermore, single-nucleotide changes within genes or a regulatory region dramatically influenced the rate of yeast sporulation,...