Control of cell type-specific gene expression and organogenesis in C. elegans

We are interested in how distinct cell types become specified and differentiate during animal development, and how these cells assemble and work together in functioning organs.

We work primarily with the nematode Caenorhabditis elegans. C. elegans is one of the simplest and best characterized multi-cellular animals, and it is a wonderful model organism to study animal development. Many of the developmental mechanisms identified in C. elegans are conserved in more complex animals including humans, and we hope our work with this simple organism will contribute to a broader understanding of biology and provide knowledge that will guide development of novel disease therapies.

Most of our work focuses on the C. elegans pharynx, a feeding organ that shares functional and molecular similarities with the heart in other animals. The pharynx consists of several different cell types, including muscles, neurons, epithelial cells, and secretory glands. We are interested in how these very different cells are produced, how they assemble into a functional organ, and how they work together during feeding.

To explore these questions, we study transcription factors that regulate gene expression in the pharynx using a variety of genetic, molecular, and imaging techniques. We are interested in identifying the gene regulatory network upstream and downstream of pharyngeal transcription factors and in understanding the molecular mechanisms of these factors' function.

Representative Publications

Huber. P., Crum, T., Clary, L.M., Ronan, T., Packard, A.P., and Okkema, P.G. (submitted). Function of the C. elegans T-box factor TBX-2 depends on SUMOylation.

Reinke, V., Krause, M. and Okkema, P. (in press). Transcriptional Regulation of Gene Expression in C. elegans. WormBook, ed. The C. elegans Research Community, WormBook, http://www.wormbook.org.

Miller RR and Okkema PG (2011) The Caenorhabditis elegans T-box factor MLS-1 requires Groucho co-repressor interaction for uterine muscle specification. PLoS Genet 7: e1002210.

Clary, L. M. and Okkema, P. G. (2010) The EGR family gene egrh-1 functions non-autonomously in the control of oocyte meiotic maturation and ovulation in C. elegans. Development 137(18): 3129-3137.

Ray, P., Schnabel, R. and Okkema, P. G. (2008). Behavioral and synaptic defects in C. elegans lacking the NK-2 homeobox gene ceh-28. Dev Neurobiol 68, 421-33.

Roy Chowdhuri, S., Crum, T., Woollard, A., Aslam, S. and Okkema, P. G. (2006). The T-box factor TBX-2 and the SUMO conjugating enzyme UBC-9 are required for ABa-derived pharyngeal muscle in C. elegans. Dev Biol 295, 664-77.