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A Reverse Genetic Approach to Test Functional Redundancy During Embryogenesis
Published on: August 11, 2010
Compensatory evolution for a gene deletion is not limited to its immediate functional network
W R Harcombe1, R Springman, J J Bull
1Section of Integrative Biology, Institute for Cell and Molecular Biology, Center for Computational Biology and Bioinformatics, University of Texas, Austin, Texas 78712, USA. harcombe@mail.utexas.edu
BMC Evolutionary Biology
|May 19, 2009
Summary
Bacteriophage T3 compensatory evolution after DNA ligase gene deletion showed that while many mutations occurred within the affected network, some outside it were crucial for recovery. This suggests broader gene interactions than previously understood.
Area of Science:
- Evolutionary biology
- Genetics
- Microbiology
Background:
- Genetic disruption of a phenotype typically drives compensatory mutations within the affected gene network.
- This study investigated compensatory evolution in bacteriophage T3 lacking its DNA ligase gene, which disrupts DNA metabolism.
Purpose of the Study:
- To test if compensatory mutations in bacteriophage T3 primarily occur within the DNA metabolism network after DNA ligase gene deletion.
- To explore the extent of gene interactions involved in fitness recovery.
Main Methods:
- Long-term adaptation experiments with two replicate lines of bacteriophage T3.
- Genome analysis to identify compensatory mutations following deletion of the DNA ligase gene.
Main Results:
- Both replicate lines showed substantial fitness recovery but remained below intact phage levels.
- Over a dozen compensatory mutations were identified in each line, with many within the DNA metabolism network.
- Crucially, several compensatory mutations occurred outside the known DNA metabolism network, with one line heavily relying on these extra-network changes.
Conclusions:
- Compensatory evolution was not strictly limited to the known interacting partners of the deleted DNA ligase gene.
- Gene interactions contributing to fitness are more extensive than currently defined by ascribed gene functions.
- Compensatory evolution provides a method to uncover genome interactions without prior knowledge of gene functions or interactions.
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