When scientists attempt to transfer genetic material into an organism, they often use an electric field, a technique called "electroporation," that makes cell walls more permeable. This sophisticated form of genetic engineering is thought to be something restricted to laboratory equipment, not nature. Yet a recent study published in the journal PeerJ reveals that electric eels — which produce an electric organ discharge (EOD) that can reach up to 860 volts — may be able to transfer genetic material through their infamous jolts.
Researchers from Nagoya University and Kyoto University in Japan learned this by placing zebrafish larvae in the same tank as electric eels, then dousing the tank in DNA that codes for a green fluorescent protein. Afterward the scientists fed a goldfish to an electric eel, prompting it to emit pulses of up to 185 volts in the tank. (Don't worry, the fish were given anesthesia.) Within a day, some of the zebrafish larvae began to glow, indicating that the electric eel's pulses had indeed caused the fluorescent gene to be transferred into the zebrafish larvae. The fluorescence lingered for three days to a week.
While this study raises tantalizing questions, it leaves many of them unanswered. The implication of this experiment is that electric eels could directly cause gene transfers that increase biodiversity or create new species. Yet as the authors admit in the study, "this investigation represents the initial exploration of the uncharted impact of electric eel EOD, but it does not directly establish its significance within the natural environment." The researchers add that further research will be required, with corresponding author Atsuo Iida from Nagoya University telling New Scientist that he plans follow-up studies on EOD and gene transfer with smaller organisms like plankton and bacteria.
