Bioinspired genotype–phenotype linkages: mimicking cellular compartmentalization for the engineering of functional proteins

The idea of compartmentalization of genotype and phenotype in cells is key for enabling Darwinian evolution. This contribution describes bioinspired systems that use in vitro compartments—water-in-oil droplets and gel-shell beads—for the directed evolution of functional proteins. Technologies based on these principles promise to provide easier access to protein-based therapeutics, reagents for processes involving enzyme catalysis, parts for synthetic biology and materials with biological components.