In the years since they were first developed, microarrays have been applied to an extraordinary range of situations. But in 2001, some researchers began to voice concerns that the increasingly ubiquitous technology was ignoring the power of classical genetics. Microarrays could be combined, they said, with genome-wide linkage analysis to give the geneticist a new way to examine complex traits.1
The technique, which some call genetical genomics, essentially treats RNA transcript levels as quantitative traits that can be mapped to quantitative trait loci (QTLs) that influence their expression. Such studies have shown that transcript levels are heritable and can be analyzed in a high-throughput manner, generating excitement about that possibility that virtually any genetic variation can be teased apart. This is a "new stage of genetics," says Robert Williams, codirector of the Center of Genomics and Bioinformatics at the University of Tennessee. "One where we can now study tens of ...
