Nutritional control of development
In order to cope with fluctuating nutrient availability, animals must sense and respond to changes in environmental conditions by altering resource allocation between growth and survival. When larvae of the nematode C. elegans hatch in the absence of food they arrest development and increase resistance to environmental stress. We use a combination of genetic and genomic approaches to elucidate the signaling networks and gene regulatory mechanisms that coordinate developmental arrest and recovery in response to changing nutrient availability. Insulin signaling regulates larval growth and arrest, but the C. elegans genome encodes 40 insulin ligands, and we are characterizing this complex signaling network. We also study gene regulation during larval growth, arrest and recovery, and we recently discovered that RNA Polymerase II is poised on the promoters of growth and development genes during arrest in anticipation of up-regulation upon feeding. We are identifying signaling pathways that contribute to nutritional control of Pol II recruitment and elongation.
