A tale of two toxins: The acquisition of defensive toxins by animals through horizontal gene transfer
Several disease-causing bacteria produce toxins that damage host cells by triggering preprogrammed cell death. Two such bacterial toxins are called cytolethal distending toxin B and apoptosis-inducing protein of 56 kDa. We discovered that diverse insect species co-opted the two bacterial genes encoding each cytotoxin through a phenomenon called horizontal gene transfer (HGT). HGT occurs when a gene from one organism is inserted into the genome of another and then is stably inherited across generations.