ABSTRACT
Cell and tissue movements play critical roles during embryonic development and homeostasis. Defects in cell migration and tissue morphogenesis often results in severe birth defects, such as neural tube defects, craniofacial anomalies, and congenital heart defects. In the past seven years, we studied a few regulatory events during cell and tissue movements, with a focus on the molecular and cellular mechanisms of neural crest cell migration. In this talk, I will mainly discuss two stories. The first one describes a novel protein Cdc42ep1 in neural crest cell migration. We demonstrated a unique activity of this protein, which coordinates the protrusive activity at cell front and the retractive activity at cell rear by interacting with Cdc42 and septin filaments respectively. The second one explores the etiology of a severe heart defect, hypoplastic left heart syndrome. Our results show that defects from the cardiac neural crest, cardiomyocytes, and endocardial tissue collectively contribute to this birth defect and imply that early intervention may be able to correct it.