A new study published in Science Advances explores the unique evolutionary processes among certain genes in certain fish species that allowed them to develop electric organs (think: the electric eel). But the findings from this study, conducted by researchers at the University of Texas at Austin, may also shed some light on the underlying genetic causes of certain human diseases.
Fish like the infamous electric eel are unique because they can, well, produce electricity from within their body. Part of the reason for this has to do with very small genetic changes that occured over millions of years to a very particular part of fish genetics: a duplicative gene that produces muscle motors, or sodium channels. Over time, this extra gene was turned off in specific muscles and turned on in other cells, which allowed fish to generate electric pulses in different areas of the body, leading to the development of organs capable of producing electricity.
In studying electric fish, researchers noted that a specific section of the gene for sodium channels that determines whether it is expressed in a given cell is missing in electric fish. The research team noted that this control feature needed to be turned off so that the gene would only be expressed in the electric organ.
Researchers examined African and South American electric fish to learn about these genetic changes. They noted that while one species had mutations in the control gene and another was missing it altogether, both fish stil evolved an electric organ, just through different mechanisms.
Interestingly, this specific section of the sodium channel-controlling gene is found in other vertebrates, including humans. The research team thinks this begs an important question: how does the expression of sodium channels in humans impact disease development?
Researchers hope to better explore how these control sections of electric fish genetic code evolved to affect sodium channels in their newly developed electric organ.