Our research is primarily concerned with the role of the cell surface in neurulation and neurogenesis. During development, cells display unique molecules at their surface and this expression changes as the maturation of each cell type progresses. Such modifications are important in cell-cell communication, motility, adhesion, recognition, and regulation. Electron microscopy of freeze fracture replicas of the developing neural tube in fish embryos show that patterns of intramembranous molecules become much more complex and numerous as neurulation proceeds.
Junctional complexes display temporal and positional patterns consistent with regional specificity.
Biochemical analysis further demonstrates that glycoprotein expression correlates temporally with events of neurulation. Another aspect of our research concerns the role of the pigmented epithelium of the retina in removing shed photoreceptor segments. Failure to remove these particles leads to degeneration of the retina. We have shown that the RPE in prehatched chicks is capable of performing this vital function even in genetic strains which display a degenerative disease. Investigations into the alteration in cell surface interactions to explain loss of this function are in progress.