BE/GEN-EN: A Genomic Approach to Physiological Tolerance, Adaptation and Dispersal

Yale University, New Haven CT

Investigators

Abstract

BE/GEN-EN: A Genomic Approach to Physiological Tolerance, Adaptation and Dispersal Leo W. Buss Yale University The world's oceans are undergoing pronounced environmental changes and, with climate alteration, are expected to continue to do so. If organisms are to survive these challenges they must alter their physiological tolerances to environmental factors or disperse to locations within their existing tolerances. At present, our knowledge of the genetic foundations of tolerance, adaptation or dispersal is scant, scattered, and idiosyncratic. However, if an appropriate system is developed, genomic technologies have the capacity to rapidly and near-exhaustively characterize all genes involved in the response to an experimental environmental challenge. At present, genomic technologies can be considered mature for only a handful of organisms and none of these are experimentally tractable marine organisms. This award has the dual objectives of generating biological resources necessary to establish Trichoplax adhaerens as a model system for marine environmental genomics, and to perform experiments intended to demonstrate the utility of this system in identifying environmentally responsive genes. In the first instance, the award will support the maintenance of a standard laboratory line of Trichoplax, the production of a normalized full-length cDNA library, and the end-sequencing of some 8,000 clones from this library. These clones will permit the production of a first generation gene expression microarray comprised of up to 5,000 unique genes. The intermediate range goal is to use microarrays in experiments to identify those genes which respond when the environmental conditions deteriorate to a point at which the animals are induced to disperse. Three distinct forms of environmental deterioration will be assessed: exposure to salinity maxima, to thermal maxima, and to critical population densities. Genes which are up-regulated, down-regulated, and those for which expression remains unaltered will be identified in Latin Square statistical design. Of particular interest will be genes whose expression is altered in a parallel fashion in all treatments, as numbered amongst these genes will be those which transduce environmental signals to elicit dispersal. While intriguing in their own right, these specific studies are expected to have the broadest impact as a proof-of-concept for the viability of marine environmental genomics. From this proof-of concept, the long-range goal will be to develop a tractable model system with which any interested scientist can study how external stimuli in the marine environment are transduced and integrated to ect changes in gene expression.