Our research is aimed at understanding the molecular bases of developmental plasticity and the genetic and evolutionary consequences of genome duplication or polyploidy in plants. Polyploid formation is very common in plants, insects, and some vertebrates. Whole-genome duplication results in autopolyploidy (duplication of a diploid genome) or allopolyploidy (combination of two or more divergent genomes). New allopolyploid species often display parental phenotypes as well as novel traits and variation. Moreover, the formation of allopolyploids results in the fixation of hybrid vigor. Thus, polyploidy provides a unique system for studying molecular mechanisms for the control of orthologous and paralogous genes after genome duplication. Genome duplication or chromosomal loss rarely occurs in animals and humans and is often associated with abnormal development and disease syndromes. It appears that plants can tolerate drastic changes in genome structure and function. This plastic nature of plant gene regulation and development is controlled at least in part by genetic and epigenetic mechanisms. We use both a model system (Arabidopsis) and an important crop (cotton) to address fundamental questions concerning genome duplication and polyploidy. Using genetic, biochemical, and computational/genomic approaches, we test fundamental hypotheses concerning the function of duplicate genes in plant polyploids. We postulate that the divergence in transcriptome and regulatory pathways between the progenitors must be reconciled in new polyploid cells; whereas sequence changes (mutations, etc.) play a role on an evolutionary time scale. Understanding mechanisms for the expression of endogenous duplicate genes will provide insights into the control of gene regulation and development in plants and animals. An example would be to reactivate or silence endogenous duplicate genes without introducing alien genes.

Financial support for our research programs is provided by the National Institutes of Health, National Science Foundation, Cotton Incorporated, and University of Texas at Austin.

The opinions expressed here are those of members in the laboratory and do not reflect the official policy of the National Institutes of Health, National Science Foundation, Cotton Inc., or the U.S. and state government.