Uncovering the strange genetic influence of electric eels

Electric eels can naturally alter the genetics of nearby organisms, a discovery previously made Nagoya University Researchers highlight the role of natural electricity in genetic changes.

The electric eel is the largest energy-creating creature on Earth. It can release up to 860 volts, which is enough to power the machine. In a recent study, a research group from Nagoya University in Japan found that electric eels can emit enough electricity to genetically modify young fish larvae. They published their findings in the scientific journal PeerJ – Life and Environment.

Electroporation understanding of nature

The researchers’ findings add to what we know about electroporation, a gene delivery technique. Electroporation uses an electric field to create temporary pores in the cell membrane. This allows molecules, e.g DNA Or proteins, enter the target cell.

Researchers have discovered that the electric eel, the largest energy-producing creature on Earth, can release enough electricity to genetically modify tiny fish larvae. Credit: Shintaro Sakaki

The research group was led by Professor Eiichi Hondo and Assistant Professor Atsu Iida from Nagoya University. They believed that if electricity flowed in a river, it might affect the cells of nearby organisms. Cells can incorporate fragments of DNA in water, known as environmental DNA. To test this, they exposed small fish in their lab to a DNA solution with a marker that glowed in the light to see if the zebrafish took up the DNA. They then introduced an electric eel and caused it to bite the feeder to discharge electricity.

Electric eels: natural drivers of genetic change

According to Ida, electroporation is usually seen as a process that exists only in the laboratory, but he was not convinced. “I thought electroporation might occur in nature,” he said. “I realized that electric eels in the Amazon River could serve as an energy source, that organisms living in the surrounding area could act as recipient cells, and that environmental DNA fragments released into the water would become foreign genes, causing genetic recombination in organisms.” Surrounding life due to electrical discharge.

The DNA of zebrafish larvae (shown in green) was modified by electricity emitted by the eel. (Zebrafish images and highlighted GFP images are overlaid). Credit: Shintaro Sakaki

The researchers discovered that 5% of the larvae had signs showing gene transfer. “This suggests that the discharge from the electric eel enhanced gene transfer into cells, even though the eel had different pulse shapes and unstable voltages compared to machines typically used in electroporation,” Ida said. “Electric eels and other organisms that generate electricity could influence genetic modification in nature.”

Other studies have observed similar phenomena in natural fields, such as lightning, affecting nematodes and soil bacteria. Ida is very excited about the possibilities of research into the electric field in living organisms. He believes these effects go beyond what conventional wisdom can understand. “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 lead to future breakthroughs,” he said.

The zebrafish larvae and the DNA solution were placed in a small container and placed inside the tank where the electric eel produces electrical pulses when the experimenter feeds on it. Credit: Shintaro Sakaki

Reference: “Discharge of electric organs from electric eels facilitates DNA transformation into adult larvae under laboratory conditions” by Shintaro Sakaki1, Ryo Ito1, Hideki Abe1, Masato Kinoshita2, Eiichi Hondo1, Atsu Iida, 4 December 2023, PeerJ – Life and Environment.
DOI: 10.7717/peerj.16596