Figure 1.
Expression level amplifies specific fitness costs. (A) Fitness costs related to protein synthesis, misfolding, aggregation, or non-specific interactions generally grow with increasing expression level, all else being equal [33,47]. By contrast, fitness costs related to function do not necessarily grow in proportion to expression level. For example, genes with both high and low fitness cost upon knockout can be found at all expression levels (B). The data in (B) are for Saccharomyces cerevisiae, taken from [29].
