Using a new technique in which models of primitive cells are constructed from the bottom up, scientists have demonstrated that the structure of a cell's membrane and cytoplasm may be as important to cell division as the specialized machinery -- such as enzymes, DNA or RNA -- which are found within living cells. Christine Keating, an associate professor of chemistry at Penn State University, and Meghan Andes-Koback, a graduate student in the Penn State Department of Chemistry, generated simple, non-living model "cells" with which they established that asymmetric division -- the process by which a cell splits to become two distinct daughter cells -- is possible even in the absence of complex cellular components, such as genes. The study, which will be published in the Journal of the American Chemical Society, may provide important clues to how life originated from non-life and how modern cells came to exhibit complex behaviors.
Keating explained that how biological cells split into asymmetrical daughter cells with very different compositions and different "fates" is something of a mystery. Cellular differentiation -- the process by which an unspecialized cell, such as a stem cell, becomes a specialized cell -- requires that different biological components reorganize themselves into each of the resulting daughter cells. For this apparently complex task to be accomplished, some important mechanism must guide both the reorganization of cellular parts and the maintenance of polarity -- the property of a cell to exhibit distinct front and back "sides" with specific placement and distribution of cellular machinery. "Many genes have been implicated in the maintenance of cell polarity and the facilitation of division into nonidentical daughter cells. It's thanks to changes in the
expression of these genes that a skin cell becomes a skin cell and a heart cell becomes a heart cell," Keating said. "But our research took a different approach. We ask
|Contact: Barbara Kennedy|