J. Lawrence Marsh, Ph.D.
Director of Developmental Biology Center & Professor

4444 McGaugh Hall
University of California Irvine
Irvine, CA 92697

Lab Tel: (949) 824-6677
Fax: (949) 824-3571
Email: jlmarsh@uci.edu

Developmental genetics The Marsh lab is currently focused on two problems.

In one project, we are interested in the mechanisms of late onset neurodegeneration in man with particular focus on the polyglutamine diseases including Huntington’s Disease. We have humanized flies by inserting mutant human disease genes such as the Huntington’s gene into flies and find that one can mimic the pathology seen in man with good fidelity. This model has been used to explore mechanisms of degeneration and to identify therapeutic strategies and pharmaceutical agents that can ameliorate this devastating disease and speed the testing of effective therapeutics in mammals. In particular, we have found that modulators of transcriptional activity including the Histone DeACetylases (HDACs) can be productively targeted to ameliorate disease severity. We are exploring the role of other transcription modifying loci as well as the role of post-translational modifications in modulating Huntington’s Disease.

In our other project, we are interested in understanding how tissues become organized into coherent structures during patterning. It is clear that secreted signaling molecules (morphogens) play a key role in tissue patterning. Using genetic strategies in Drosophila, we find that the regulatory networks between morphogens can generate a robust self-organizing system that involves autoactivation and cross inhibition. The regulatory network between Wingless (Wg or Wnt in vertebrates) and Decapentaplegic (Dpp, a relative of the Bone Morphogenetic Family of proteins) that drives development of the fly leg is such an example. We are studying the mechanism of cross signaling in this self-organizing system. While such a system is elegant, it is clear that corruption of such a network by mutation is a recipe for cancer. In collaboration with others, we have extended these studies by finding that human tissues employ similar networks of regulation in tissues such as the colon and breast. We are currently investigating the molecular consequences of oncogenic mutations in these pathways and the regulation of the down stream transcription factors (TCFs) that transduce these signals.

Recent Publications