Prediction of cross-fitness for adaptive evolution to different environmental conditions: Consequence of phenotypic dimensional reduction

How adaptive evolution to one environmental stress improves or suppresses adaptation to another is an important problem in evolutionary biology. For instance, in microbiology, the change of resistance to one antibiotic by resistance acquisition by another drug is a critical issue that has been investigated as cross-resistance. Recent experiments on bacteria have suggested that the cross-resistance of their evolution to various stressful environments can be predicted based on the transcriptome changes after evolution under the corresponding stresses. However, there are no studies so far that explain a possible theoretical relationship between cross-resistance and changes in the transcriptome, which causes high-dimensional changes to cell phenotype. In the present paper, we show that a correlation exists between fitness change in stress tolerance evolution and response to the environment, using a cellular model with a high-dimensional phenotype and establishing the relationship theoretically by formulating a macroscopic potential theory against environmental and genetic changes. Finally, we applied the theory to experimental data on bacterial evolution under antibiotics, which demonstrates the theoretically predicted correlation between the fitness changes by evolution and transcriptome changes upon environmental stresses. Thus, evolution is predicted from transcriptome information in response to stresses before evolution.