Understanding the molecular pathway responsible for this phenomenon is a research objective for MBL investigator William R. Jeffery, a former director of the MBL Embryology course and professor of biology at the University of Maryland. "The question I'm interested in is not only what mechanisms are involved in regeneration, but how exact [photoreceptor] patterns are formed," Jeffery says.
Following up on previous research, in which he experimentally induced variations in the number of photoreceptors that regenerate by manipulating the siphon's diameter, this summer Jeffery will test the role of the Notch signaling pathway, a highly conserved molecular cascade that determines how an embryo forms. If Jeffery is on the right track, not only will he develop a model of regeneration in sea squirts, but in salamanders as well. Basic research on animal regeneration is a foundation for a major goal in medicine: Learning how to guide human stem cells to regenerate new tissues or organs.
Cells are intrinsically artistic. When the right signals tell a cell to divide, it usually splits down the middle, resulting in two identical daughter cells. (Stem cells are the exception to the rule.) This natural symmetry is visible on the macroscopic scale as well. All living creatures, be they mushrooms or humans, are visibly symmetric, a product of our cells' preference for equilibrium.
Scientists at the MBL's Whitman Center for Visiting Research are curious to know what cues tell a cell to divide at the center. Fred Chang, professor of microbiology at Columbia University, his pos
|Contact: Diana Kenney|
Marine Biological Laboratory