Mikroevolution hos bakterier: genetiska och fysiologiska responser till begränsning av tillväxtpotential.
Tidsperiod: 2013-01-01 till 2015-12-31
Projektledare: Diarmaid Hughes
Budget: 1 800 000 SEK
This proposal addresses examples of bacterial microevolution, and the genetic and physiological adaptations that occur, in response to impaired growth potential. In one sub-project the evolution and physiological significance of codon usage bias will be experimentally studied. We will measure the fitness costs of reduced bias in highly expressed genes, and the rates and trajectories of codon evolution under growth selection. In a second sub-project, an hypothesis for bacterial growth regulation coming out of our work on a slow-growing EF-Tu mutant (namely, that codon-specific pausing acts as a trip wire mechanism to trigger mRNA degradation) will be experimentally tested. In addition, the reason for the essentiality of the endonuclease RNase E will be elucidated.In a third sub-project, the fitness costs and evolution of genomic adaptation to a chromosome inversion will be experimentally studied. In particular we will test whether operon structure and mRNA sequence places a fitness barrier to chromosome rearrangements.