Genes As Time Machines
3.5 Billion Year-Old Genes Resurrected to Serve as Probes of Early Life on Earth.
Scientists at the Foundation for Applied Molecular Evolution, University of Florida (both at Gainesville, FL) and DNA2.0 (Menlo Park, CA) today publish a study in the journal Nature where more than 20 ancient genes were resurrected from organisms that lived between 500 million to 3.5 billion years ago.
"By studying proteins encoded by these primordial genes, we are able to infer information about the environmental conditions of the early Earth" said Dr. Eric Gaucher at the Foundation for Applied Molecular Evolution and lead scientist of the study. "Genes evolve to adapt to the environmental conditions in which an organism lives. Resurrecting these long extinct genes gives us the opportunity to analyze and dissect the ancient surroundings that have been recorded in the gene sequence. The genes essentially behave as dynamic fossils."
The researchers chose a gene that encodes a protein which captures the environmental temperature of the gene's host organism. In essence, the resurrected genes are ancient thermometers. These 'thermometers' were used to provide evidence that the oldest bacterial life forms lived at a hot temperature of 75 degrees C (~165 degrees F) 3.5 billion years ago, and slowly cooled to a temperature of 40 degrees C (~100 degrees F) by 500 million years ago.
"Remarkably, our results are nearly identical to geologic studies that estimate the temperature trend for the ancient ocean over the same time period. The convergence of results from biology and geology show that Earth's environment has continuously been changing since life began, and life has adapted appropriately to survive," said Dr. Gaucher.
"Although the concept of ancestral gene resurrection was proposed more than forty years ago, the development of efficient gene synthesis has only recently enabled the creation of the ancestral genes required for a study like this" said Dr. Sridhar Govindarajan, co-author of the paper and scientist at DNA2.0, the gene synthesis company that built the ancestral genes. "Gene synthesis allows for a direct route from a calculated gene sequence to a protein that can be tested for function in the laboratory."
Dr. Omjoy Ganesh, a structural biologist at the University of Florida, also contributed to this research.
About the Foundation for Applied Molecular Evolution
FfAME is a non-profit research organization combining computational, chemical, molecular and life sciences to uniquely create a vertically integrated approach that generates opportunities to transfer technology from basic research to meet demands in commerce and medicine. For more information, visit http://www.ffame.org
DNA2.0 is the largest US provider of synthetic genes, serving customers globally in the pharmaceutical and biotechnology industries as well as in academia. The company is also applying machine learning to protein engineering through their ProteinGPS(TM) platform. For more information, visit http://www.DNA20.com