Study Suggests Electric Eels Can Alter Genes of Nearby Fish
Researchers at Nagoya University in Japan, led by Professor Eiichi Hondo and Assistant Professor Atsuo Iida, have shown that the relatively powerful discharge (up to 860V) of electric eels is enough to alter the genes of nearby zebrafish larvae. This phenomenon occurred through a process known as electroporation or gene transport via electricity.
In a study published in PeerJ—Life and Environment, Hondo and Iida hypothesized that since electricity is conducted through water, it is possible that it could affect organisms near the charge. Apparently, their hunch was right.
Electroporation is a process in which an electric field creates temporary pores in a cell’s membrane, allowing DNA molecules to enter the cell.
Quoted in a news brief by Science Daily, Iida said, “I realized that electric eels in the Amazon River could well act as a power source, organisms living in the surrounding area could act as recipient cells, and environmental DNA fragments released into the water would become foreign genes, causing genetic recombination in the surrounding organisms because of electric discharge."
To test their hypothesis, the team exposed larvae in the lab to a DNA solution with a marker that glowed if the zebrafish had taken the DNA. Next, they induced an eel to discharge electricity.
They found that about 5% of the fish contained markers indicating gene transfer.
“This indicates that the discharge from the electric eel promoted gene transfer to the cells, even though eels have different shapes of pulse and unstable voltage compared to machines usually used in electroporation,” Iida said.
Some of the larvae exhibited green fluorescence, whereas the control group without electrical stimulation showed little. This suggested to the team that electric organ discharge (EOD) from the eels could potentially be an electroporator to transfer DNA into eukaryotic cells or those with a clearly defined nucleus.
The authors cautioned that their initial exploration does not serve to directly establish its significance within the natural environment, and further research is needed. But Iida thinks their results indicate that “electric eels and other organisms that generate electricity could affect genetic modification in nature."
According to the Science Daily brief, Iida is intrigued by electric field research in living organisms. "I believe that attempts to discover new biological phenomena based on such ‘unexpected’ and ‘outside-the-box’ ideas will enlighten the world about the complexities of living organisms and trigger breakthroughs in the future."