| Abstrakt: |
Weuse simplemodels of the costs and benefits ofmicrobial gene expression to show that changing a protein's expression away from its optimumby 2-fold should reduce fitness by at least 0:2 . P,whereP is the fraction the cell's protein that the gene accounts for. As microbial genes are usually expressed at above 5 parts permillion, and effective population sizes are likely to be above 106, this implies that 2-fold changes to gene expression levels are under strong selection, as Ne . s ⪢ 1, where Ne is the effective population size and s is the selection coefficient. Thus, most gene duplications should be selected against. On the other hand, we predict that for most genes, small changes in the expression will be effectively neutral. [ABSTRACT FROM AUTHOR] |
