Laboratory of Todd Vision
Department of Biology
University of North Carolina at Chapel Hill

Microevolution of genome rearrangements

Comparisons of nuclear gene order between related species in eukaryotes invariably reveal a substantial number of genes that occur in noncolinear positions, suggesting that small genomic segments are occassionally transposed to new positions . For such fixed differences to occur, these gene order microrearrangements must, at some point, have been polymorphic within species. Recent studies have, in fact, revealed gene order polymorphisms in a variety of eukaryotic organisms. Though several mechanisms have been proposed that could cause such rearrangements, it is not clear which mechanisms are actually responsible for this naturally occuring variation. We are equally ignorant of the incidence of such polymorphisms within species, their phenotypic consequences, and the roles of microevolutionary forces such as selection and drift in governing their fate.

To help address these issues, we have developed a technique to systematically and comprehensively identify such genome microtranspositions in yeast using microarray technology. This technology, which can be applied to yet more complex genomes, for the first time reveals, in an unbiased fashion, the patterns of microrearrangement present in eukaryotic genomes and enables us to study their origins and functional consequences.