Genotype networks in metabolic reaction spaces

Given a growth medium, only certain sets of reactions (defining genotypes) will be able to produce pre-specified target biomass components. We investigate this question insilico using reactions in KEGG database and in an E. coli metabolism model. By sampling the space of all possible sets of reactions, we determine the characteristics of genotypes which grow on different minimal media. In particular we find that mutational robustness has a narrow distribution, and that environmental robustness is only weakly associated with mutational robustness.

This work has been done in collaboration with Jürgen Jost, Olivier C. Martin and Andreas Wagner.