JUPITER, Fla., March 17 Recent laboratory experiments which seek to recreate the formation of the first living cells from the basic chemical building blocks of nature are shedding new light on how life may have occurred on earth and on other planets, biologist Jack Szostak and chemist Brian Paegel said late yesterday in the annual Lasker Foundation Lecture on the Florida campus of the Scripps Research Institute.
In his remarks, "The Origin of Cellular Life and the Emergence of Darwinian Evolution," Szostak, winner of the 2006 Lasker Award for Basic Medical Research and 2009 Nobel Prize in Medicine, focused on his latest studies, which seek to reconstruct the pre-evolutionary formation of living systems from basic chemical building blocks. "If it proves to be easy to build simple cells in the laboratory," Szostak said, "it might show that life could have formed quickly on earth and perhaps even on other planets in similar ways."
In "Landscapes for Darwinian Evolution," Paegel, an assistant chemistry professor at Scripps Research Institute's Florida campus, described the basic implications and practical applications of his research. "Both Jack and I are working on how life might have begun on our planet because figuring that out would begin to answer most of the questions we have about ourselves and our universe," Paegel said. "It would explain whether or not we are unique in the universe, or if this really is the natural consequence of oxygen, carbon, and other organic material coming together."
The Lasker Lecture is part of a series of forums presented by the Lasker Foundation designed to support and promote a public dialogue over critical issues involving the biological sciences. The inaugural Lasker Lecture, "Reading the Human Genome: Genes and Brains," by biologist and two-time Lasker laureate Sydney Brenner, took place at the Fred Hutchinson Cancer Research Center in Seattle in November 2009. Yesterday's lectures were followed by a public discussion moderated by Robert Bazell, chief science and health correspondent of NBC News.
Szostak's work focuses on the use of fatty acids - the result of the breakdown of fats - to produce synthetic membranes or vesicles; the body uses these same membranes to carry nucleotides - the building blocks of both RNA and DNA - into the cell. Fatty acids, which are simple in their chemical structure, may have been part of the chemical soup found on early earth that gave way to simple cells that eventually evolved into recognizable life forms.
During its next phase, the research will shift from studying these membranes into the realm of genetics. "We are looking at the replication of primitive genetic materials, which is something of a challenge," Szostak said. "But if we can solve the problem of chemical replication of some genetic material, then we may be close to building simple living cells. Ultimately we hope this will lead to a more complete explanation of how life itself began on earth."
Paegel outlined his efforts to come to a better understanding of the processes required to construct those membranes in the first place. "If you can build it, you can understand it," he said, "Once it's built, we can use it to actually direct the evolutionary process where we want it to go. The other aspect of our work is the practical development of fatty acid membranes for drug delivery. We devote countless hours to screening for drugs, so why not screen for delivery systems, too?"
Paegel explained that conventional methods for generating molecular compartments aren't terribly effective. To solve that problem, he and Scripps Research scientist Gerald Joyce of The Scripps Research Institute's La Jolla, California, campus perfected a microfluidic processor designed to control the synthesis of these basic membrane structures and create a platform to observe molecular evolution in real time.
Paegel's innovative device used a replicating molecule that stitched together strands of RNA. After just 70 hours of replication, the molecule could duplicate RNA 90 times more efficiently than it did at the beginning, a clear confirmation of the power of evolution.
The study, "Darwinian Evolution on a Chip," was published in the journal Public Library of Science in April 2008.
SOURCE Albert and Mary Lasker Foundation