Grant: $411,050 - National Science Foundation - Jun. 4, 2009
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Award Description: The adaptation of organisms to their environment is one of the most conspicuous features of evolution. Many studies have focused on the dynamics of adaptation, but relatively little is known about the mechanistic basis of these dynamics. With the advent of technologies that allow researchers to screen and precisely manipulate genomes this is changing. We propose to apply these technologies to a defined sequence of mutations underlying adaptation to an experimental environment. The results will provide new insights into the mechanism, generality, and consequences of adaptation. A long-term goal of our research is to examine how genetic and ecological factors affect adaptation. The goal of this project is to examine how genetic background and external environment, individually and in combination, affect the response of organisms to adaptive mutations, and to determine whether these effects can be predicted from known relationships between environments and genotypes. Our experiments are founded upon the genetic definition of the first five adaptive steps of a laboratory population of Escherichia coli. We plan to transfer these mutations to ten different E. coli strains - eight natural isolates, one lab strain and the original experimental ancestor - nested within a defined phylogeny. We will use these strains to address two broad questions. (1) How does the external environment influence the effect of single adaptive mutations? Our working hypothesis is that there will be extensive interactions between mutations and the external environment and that these interactions will cause the fitness effect of mutations to differ across environments. We further predict that fitness effects of single mutations will tend to correlate with the degree of environmental similarity. (2) How does the genetic environment influence the effect of single adaptive mutations? Our working hypothesis is that adaptive mutations will interact with many aspects of the genetic environment and that these interactions will cause the fitness and phenotypic effects of mutations to differ between genetic backgrounds. We further predict that these interactions will be mediated by relatively few of the differences between a given pair of genetic backgrounds.
Project Description: This grant began July 15 2009. Since that time the collaborating PI's have met once to plan logistics of beginning the grant. We have begun identifying a series of species and strains closely related to our focal strain, Escherichia coli B. These strains, together with the natural isolate strains identified in our proposal are now the focus of attempts to construct a broad phylogeny. In particular we are placing emphasis on choosing additional strains that have fully sequenced and annotated genomes. This fact will allow us to apply a genomic comparison algorithm recently developed by one of us (V. Cooper) to our strains. We anticipate this additional resolution of genome-wide comparisons will enable much greater insight into potential mechanisms behind identified gene x genotype interactions as we begin to introduce our panel of conditionally beneficial mutations into these strains. This resolution will be especially important in allowing us to examine the transcriptional response of different strains to common mutations. Additionally we have begun pilot experiments to test the effect of our five beneficial mutations on the diet breadth of our reference strain. The results from these experiments will allow us to refine the collections of environments we follow up in more detail. Finally, we have begun to recruit graduate students to work on this project – one student has been identified and have begun background reading relevant to this project in each of the PI’s labs.
Infrastructure Description: n/a
Jobs Summary: The University of Houston values research as one of its top institutional priorities; it is a vital part of the university’s strategic vision. To take our place among the nation’s great metropolitan research institutions, we are building a well-rounded, robust research core group , made up of outstanding faculty and staff. This core group will ensure production of innovative research important to our community and beyond. The ARRA funding is critical to the building of that research core group. The workforce for ARRA funded research projects may include academic faculty and staff with the following titles: Principal Investigator, Co-Principal Investigator, Professor, Associate Professor, Assistant Professor, Research Scientist, Research Professor, Research Associate Professor, Research Assistant Professor, Senior Research Scientist, Graduate Research Assistant, Research Associate, Lab Technician, Research Lab Manager, Post Doctoral Fellow. Each of these titles contributes to the future of discovery — scientific and otherwise. (Total jobs reported: 0)
Project Status: Less Than 50% Completed
This award's data was last updated on Jun. 4, 2009. Help expand these official descriptions using the wiki below.