2009 Public Lecture Series
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Programming Stem Cells: Dressed to Express (or Repress)
Wednesday, May 6, 2009
The identity of every cell type in our bodies, from "stem" to stern, is specified by which genes are turned on to produce messenger RNA and its protein products, and which are turned off. This gene expression is controlled in part by transcription factors, which are proteins that bind to specific genes. New research indicates that a handful of transcription factors are critical for controlling the "stemness" of cells; introduction of these factors into mature, differentiated cells allows their reprogramming to a stem cell-like state. Gene expression is also controlled by proteins called histones that bind to most of the DNA in a cell. The histones can be modified by enzymes that attach specific small chemical groups to specific sites; this modification varies at different genomic sites, and can therefore "mark" specific genes. Recent investigations have shown that the histones and their modifications are particularly important in stem cell regulation, and provide an "epigenetic" signature of stem cell identity and potential. Remarkably, some of the enzymes that are found to be important for this function in human stem cells were first discovered in studies of regulation of cell type during development in fruit flies.
Related Links
- Public Broadcasting System
- University of Utah, Genetic Science Learning Center
- University of Missouri-Kansas City
- Glossary
Randall Morse, Ph.D.
Dr. Morse grew up in Michigan and received his B.A. in chemistry and mathematics at Kalamazoo College. He performed his graduate work on biophysical studies of metal-containing proteins, receiving his Ph.D. in chemistry from Caltech in 1981. He then changed research areas considerably to do postdoctoral work in molecular biology, first at Columbia University and then at the National Institutes of Health. He joined the Wadsworth Center in 1993 where his laboratory has focused on studying regulation of gene expression using yeast as a model system. He recently began a collaboration with Dr. Sally Temple of the New York Neural Stem Cell Institute to study the epigenetics of neural stem cells. Dr. Morse is currently chief of the Laboratory of Molecular Genetics at Wadsworth and professor in the Department of Biomedical Sciences at the University at Albany School of Public Health. He is married with two children and enjoys travel, reading, bicycling, tennis and (fortunately) work.