Igor B. Dawid
Our group studies the frog Xenopus laevis and the zebrafish Danio rerio to obtain insights into mechanisms of vertebrate development. We use molecular and genetic screens to identify genes that regulate development, with an emphasis on signaling pathways and cell interactions. In particular, we have carried out a screen in zebrafish using in situ hybridization to identify differentially expressed genes, and have applied DNA microarray technology to identify genes with regionally or temporally restricted expression in the frog and fish embryo. Recent projects have included studies on the regulation of cell movements during gastrulation by the Wnt pathway. We have identified a guanine nucleotide exchange factor that has a critical role in this process in the frog embryo. In another project we are studying factors that modulate the Fgf pathway. Previously we have identified and studied feed-back inhibitors of Fgf signaling that are required to limit the strength of the signal during many developmental processes. More recently we have studied a transmembrane protein, Lrig3, that modulates Fgf and Wnt signaling and is required for neural crest formation. Lrig3 interacts with Fgf receptors and appears to regulate the availability of the receptor in the cell. The mechanism of Lrig3 function is a continuing subject of study. Additional current projects aim to elucidate mechanisms of axis specification in the Xenopus and zebrafish embryo. We are studying molecular events that specify the initial dorsal-ventral axis through the regulation of transcription factor activity by interaction with a specific ubiquitin E3 ligase. The dorsal axis in the embryo is centered on the notochord, the defining feature of the chordate phylum. We study the role and regulation of secretory pathways in notochord formation with the aid of groups of genes that we identified in DNA microarray experiments. In a distinct collaborative study we apply the microarray technology to a study of the development of the pineal gland in the zebrafish.
Lab MembershipsDawid Lab (Principal Investigator/Director)
Tufts Center for Regenerative and Developmental Biology
200 Boston Ave.
Web Page: http://sdb.nichd.nih.gov/
301 496 4448