Research topics:
The Marx laboratory uses experimental evolution as an approach to address the selective pressures and varied outcomes of
adaptation of microbial populations. Current projects include:
- Systems-level physiological basis of selection and epistasis in adaptation of strains bearing engineered horizontal gene
transfers. Can we move toward being able to quantitatively predict the probability of various evolutionary outcomes, and how
the mutations along these trajectories interact?
- Experimental evolution of multi-species, synthetic consortia to integrate studies of the physiological, ecological and
evolutionary aspects of cooperation and coevolution in microbial communities. Can metabolic models guide predictions as to
the function and adaptation of novel assemblages, particularly conditions where costly cooperation is selectively
advantageous?
- Distribution of fitness effects, identity and interaction of beneficial mutations available for adaptation. How can we
characterize the raw material available for adaptation and how this changes as adaptation to a particular environment slows
down?
- Investigation of fitness tradeoffs and adaptive diversifications associated with specialist vs. generalist lifestyles. Can we
predict when to utilize more than one substrate simultaneously vs. forming independent ecotypes?
- Transposable elements as key variation in adaptation. What roles do mobile elements play in the evolution of laboratory and
natural populations?
- Balance of costs and benefits associated with gene expression and codon usage. What drives selection upon codon usage in
genomes?
- Physiological function of hopanoids in Methylobacterium. What role do these key geological biomarkers play in this
present-day model organism, and what inferences can thus be drawn about ancient environments?
Funding Resources:
- National Institutes of Health: ARRA Supplement to "Systems-level physiological basis of selection and epistasis in adaptation." (3R01GM078209-03S1, 8/17/2009-7/31/2011, $275,333)
- National Science Foundation: "CAREER: Distribution of Fitness Effects, Identity and Interaction of Beneficial Mutations Available for Adaption." (DEB-0845893, 8/1/2009-7/31/2014, $702,452)
- Agouron Institute Postdoctoral Fellowship in Geobiology: "Investigating the physiological function of hopanoids and methylhopanoids in Methylobacterium extorquens AM1." (AI-F-GB9.08.2, Supporting Alexander S. Bradley, 01/01/08-12/31/09, $108,000)
- National Institutes of Health: "Systems-level physiological basis of selection and epistasis in adaptation." (PI for 1R01GM078209-01A1 (co-PI: Daniel Segrč, Boston University), 7/10/2007-5/31/2012, $1,463,216)
- Microbial Sciences Initiative, Harvard University. Summer undergraduate fellowships (Seven from 2007-2009, $28,000 in total)
- The Clark/Cooke Fund: "Evolution of metabolic specialization and tradeoffs in laboratory populations." (1/1/2006-12/31/2007, $5932)
- National Science Foundation Microbial Biology Special Starter Grant: "Adaptation, tradeoffs and specialized metabolism in experimental and natural populations." (IOB-0612591, 3/1/2006-2/28/2007, $49,995)
- The William F. Milton Fund: "Influence of environmental factors on the emergence of cooperation and coevolution in defined, multi-species microbial consortia." (1/1/2006-12/31/2006, $35,000)
- Lead Proposer, DOE 2006 Microbes Community Sequencing Program, "Horizontal gene transfer and genome rearrangements in the evolution of specialized metabolism in Methylobacterium species."
- National Science Foundation Microbial Biology Postdoctoral Fellowship, "Horizontal gene transfer and the evolution of specialized metabolism." (DBI-0301202, 9/1/2003-4/30/2005, $83,333)
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