Scientist studies evolution of 'electric organs'


Dr. James Albert jabs the exposed end of a length of coated wire into the water of a small aquarium, home of a tiny electric eel the size of pocket comb.

The associate professor of biology at the University of Louisiana at Lafayette waves the metal prongs around like a wand, sending electrical impulses into a black box at the other end of the wire. The electronic box crackles like an old transistor radio searching for a signal. The popping sounds grow louder as his hand nears the eel, which emits an electric current it uses to stun prey, defend itself, navigate and communicate.

Albert is an ichthyologist, or a scientist who studies fishes—their anatomy, evolution, behavior, genetics, and, during a 10-year research project, their potential for medical advances. His favorites, and the ones he has studied the most, are electric eels, which get their name from their long body shape and are actually a specialized kind of fish.

“Electric fishes are the masters of electricity,” Albert said. “All animals make electricity. Our brains run on electricity, and every time a muscle contracts, it’s because of electricity. But electric fishes can make more of it, and they have control of it.”

Albert co-authored an article entitled “Genomic Basis for the Convergent Evolution of Electric Organs” that was recently published in Science magazine. The article details the work of a team of 16 scientists who assembled the entire genome—or the complete set of genes—of the electric eel.

“Electric fish have a whole new cell type that mammals don’t have, and the question is, ‘What genes were changed to allow the origin of this new cell type?’ ” he said.

Researchers compared a group of electric fish from South America with another group from Africa as part of the study. They discovered that although each group evolved electric organs independently, similar genes were responsible for the development of these organs inside the fish.

Electric eels produce electricity using several organs, which contain flat, disc-shaped cells, called electrocytes. The electrocytes, which are stacked atop each other like batteries in a flashlight, generate electricity.

The project, which was led by Dr. Michael Sussman of the University of Wisconsin-Madison, was conducted to provide a genetic blueprint for electric fish that could be used in medical research, according to Albert.

“There’s a whole new generation of implantable devices that are coming down the pipeline, pacemakers for example. How are we going to power them? Are we going to put artificial batteries in these devices? Or are we going to be able to use our own metabolic activity to power them? That’s what an electric fish does. It has modified muscles that generate electricity.”

As the project’s only anatomist, Albert’s work included dissecting the electric organs, spinal cords, brains, kidneys, skin and other tissue to help ascertain the genetic profiles of the electric fishes.

His main interest in the project, he says, was less biomedical than learning more about the evolutionary history of electric fishes. “What I really wanted was the genome of the electric eel, to understand the evolution of electric fish.”

Learn more about "Genomic Basis for the Convergent Evolution of Electric Organs" on Science magazine’s website.

Science was founded in 1880 by inventor Thomas Edison. The peer-reviewed journal, which has grown into the world's leading outlet for scientific news and research, reaches more than one million readers in print and online, according to information at