These Mycoplasma capricolum bacterial cells have absorbed a genome engineered from a closely related bacterium, Mycoplasma mycoides.Credit: Thomas Deerinck, NCMIR/Science Photo Library Researchers have resurrected ‘dead’ bacterial cells by replacing their defunct DNA with the working genome of another species. AI can write genomes — how long until it creates synthetic life? The feat — reported on the preprint server bioRxiv this month1 — could boost efforts to re-engineer microbial life by moving entire genomes into bacteria to imbue them with useful properties, such as making drugs or biofuels. Such genome transfers, including the one that gave rise to these ‘zombie cells’, have so far been accomplished only between species within a single bacterial class. But if researchers can routinely make zombies from other bacteria, the approach could be used to test engineered genomes from more commonly studied species, such as the laboratory staple Escherichia coli.…