A common aquarium fish has made a splash as the source of a genetic discovery concerning human skin color.

An international team of scientists, including Nancy Mangini, associate professor of anatomy and cell biology at Indiana University Northwest, has discovered that a gene which controls pigmentation in zebrafish also plays a role in human skin coloration. Their work was featured on the cover of the journal Science in December and was supported by the National Science Foundation.

Led by Keith Cheng of Pennsylvania State University, the team first determined that the gene, called golden , regulated pigmentation in the golden zebrafish, which are lighter and have paler stripes than typical zebrafish.. The team went on to prove that the golden gene was responsible for the differences between the zebrafish variants. The researchers then used an online database of human genome information to find a similar gene in humans. They found that a specific change in the human counterpart to golden was prevalent in individuals from lighter-skinned European populations, while the gene without the change was linked to the darker pigmentation of West Africans and East Asians.

The golden gene appears to regulate the flow of calcium, which may play a role in the production of the pigment melanin.

“This gene controls calcium, and we discovered that a minor change causes differences in pigmentation,” says Mangini, who does research on the importance of calcium transport in the eye and teaches pharmacology at the IU School of Medicine branch on the IUN campus in Gary. “This same gene was found to be directly related to variations in human skin color.

“In evolutionary terms,” she continues, “this means that this gene is very important to the life of cells and was conserved from the time that fish evolved, all the way to humans.”

Mangini adds that the discovery of a gene that regulates skin pigmentation has potentially wide-ranging health implications. “In cells other than pigment cells, this gene might cause differences in the way cells react to medicines,” she says. “So skin color might be an indicator of the potential for other health problems. The more we know about how genes differ between individuals and among populations, the better we will be able to tailor medicines to treat specific medical conditions to which they are more prone.”

For more on Mangini's work at the IU School of Medicine—Northwest, see shaw.medlib.iupui.edu/nwcme/smplemang.html