Electric Eels Could Alter DNA Using Gene Transfer via Intense Electrical Pulses [Study]

Electric eels can alter the DNA of those that exist around them. They could introduce specific genes through the use of electroporation.

Electric Eels Could Alter DNA Using Electroporation

A Nagoya University research team has shown in a new study that the discharges of electric eels can genetically alter small fish larvae.

A typical lab approach is to use electricity to change the genetic makeup of microbes and introduce particular genes into different types of bacteria. The method, called electroporation, is a biophysical procedure that makes transient holes in cell membranes big enough to let desired proteins or DNA into the target cells. The cells continue to express this new genetic information as they live and mend these pores.

Eiichi Hondo, a professor of agricultural sciences at Nagoya University, and Atsuo Iida, an assistant professor in the same department, co-led the research team. The partners hypothesized that electricity pulses in a body of water could also affect adjacent creatures (in addition to the resident bacteria) by encouraging them to take up DNA fragments floating in the water. This theory was based on Professor Iida's electroporation knowledge and fish experience. We refer to these pieces of DNA as ambient DNA.

To put it succinctly, the electric eel specialist Professor Iida said that electroporation is not merely a lab procedure. It might also be a result of nature.

"I thought electroporation might happen in nature," Professor Iida explained. "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 present in the water would become foreign genes, causing genetic recombination in the surrounding organisms because of electric discharge."

Since genetic engineering has a well-established method for transferring genes through powerful electrical pulses, Professor Iida and colleagues hypothesized that electric eels might be a living gene transfer device in their watery habitat.

Professor Iida and associates exposed lab-raised larval zebrafish to an electric discharge from an electric eel while the fish were submerged in a DNA solution containing a genetic marker encoding a green fluorescent protein. Next, they placed an electric eel inside the enclosure and bit a feeder to cause it to release electricity. The cells of the zebrafish larvae would glow green if they had absorbed the DNA.

Despite variations in the electric eels' pulses, they discovered that 5 percent of the zebrafish did flash green, offering verifiable proof that gene transfer had occurred.

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Electric Eels

Electric eels are known for their serpentine-like appearance. However, they're not eels. They are classified scientifically more like catfish and carp.

The massive electrical charge these well-known freshwater predators can produce to stun prey and deter predators gives them their name. About 6,000 specialized cells called electrolytes, which store energy like small batteries, are found in their bodies' electric organs. These cells release simultaneously when they sense danger or an attack on their target.

Electric eels can grow to enormous sizes-they can weigh up to 44 pounds and reach lengths of up to 8 feet. They are often dark green or greenish on top and yellowish underneath, with long, cylindrical bodies and flattened heads.

It is quite uncommon for electric eels to kill humans. Nevertheless, following a startling shock, people have been known to drown in shallow water, and repeated shocks can result in cardiac or respiratory failure.