Martin C. Raff
University of London
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Primary Section: 22, Cellular and Developmental Biology Secondary Section: 24, Cellular and Molecular Neuroscience Membership Type:
International Member
(elected 2003)
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Research Interests
My colleagues and I have been interested in how developing animal cells decide whether to live or die, grow or stop growing, proliferate or stop proliferating, or differentiate into one cell type rather than another. We have addressed these questions mainly in the rodent central nervous system (CNS), using the optic nerve and retina as model systems. Not surprisingly, we found that all of these decisions depend on a combination of cell-cell interactions and cell-intrinsic programs. For example, we found that many, if not all; mammalian cells require extracellular signals from other cells to avoid apoptosis, which is mediated by an intracellular suicide program. In the optic nerve, we identified a number of the molecules that control these types of decisions in the oligodendrocyte cell lineage, the cells that make myelin in the CNS. We have been especially interested in the timing mechanism that stops cell division and initiates differentiation at the appropriate time in development. The timer depends on a number of intracellular proteins, whose concentrations increase or decrease progressively as the precursor cells proliferate. To help understand how the size of an animal or organ is determined, we studied the factors that control the final number of oligodendrocytes in the optic nerve and those that determine the size of a developing Schwann cell when it divides.
