Department of Molecular Biology
The long-term goal of our research is to understand the molecular mechanisms underlying adaptive traits. The majority of the Weigel group investigates genetic diversity, which is being studied on several different levels. In addition to forward genetic analyses of wild Arabidopsis thaliana strains, we are examining sequence variation and its impact on a spectrum of phenotypes, including hybrid performance, on a whole-genome, whole-species scale. Such studies benefit tremendously from knowledge about the genomes of other species, and we have taken the lead in assembling genome sequences for several A. thaliana relatives.
In all of these areas, second-generation sequencing is playing a major role. The department has been at the forefront of developing bioinformatic methods for the analysis of Illumina (Solexa) data, and has been using these for a range of applications, from sequencing A. thaliana strains to mapping of transcription factor binding sites and one-step mutation identification.
We have analyzed developmental morphology and RNA expression dynamics associated with natural variants of ra1 including an allele that shows tight genetic linkage to a branch-number QTL in maize and the ra1 orthologs in Miscanthus sinensis and Sorghum bicolor. In each of these examples we see a correlation between timing and/or levels of ra1 expression and lateral branch meristem determinacy in the inflorescence. Recent work in my lab extends this analysis by comparative genomics and functional analysis in rice and broader sampling of the grass phylogeny. Our findings suggest a general role for the ramosa genes in regulating long-branch architecture in cereals, and implicate the ramosa pathway in the evolutionary diversification of grass inflorescence development.