PARADOXICAL POISON AND ANTIDOTE. “In prokaryotes, conjugative plasmids often encode for the simultaneous production of long-lived toxins and short-lived antitoxins. When these are present together, the toxin is harmless to the host. However, if one daughter cell is cured of the plasmid, it will inherit toxic cytoplasm without a source of antitoxin and will die. While this is easily explained as a ‘selfish’ adaptation on the part of the plasmid, chromosomally-encoded toxin-antitoxin systems probably do not function in gene-level competition.”
https://www.linkedin.com/redir/general-malware-page?url=http%3A%2F%2Fwww%2eesciencecentral%2eorg%2Fjournals%2Fare-internal-death-promoting-mechanisms-ever-adaptive-2329-9002%2e1000113%2epdf