Fish Give Clues to Human Skin Color Changes

Mar. 23 -- FRIDAY, Dec. 14 (HealthDay News) -- Research in the tiny stickleback fish could shed light on skin color changes in humans.

A team at Stanford University School of Medicine has spotted a gene that's responsible for color differences in both species.

While it may seem that the small fish and humans have little in common, they share many similarities, noted study senior author David Kingsley, professor of developmental biology. Both the sticklebacks and humans migrated out of ancestral environments to new locations a few thousand generations ago and both developed new traits -- such as skin color changes -- to be able to live in those new settings.

Kingsley and his colleagues compared DNA from lighter and darker sticklebacks and found that the lighter fish had mutations in a gene called Kit ligand. The researchers then analyzed DNA from people with different skin colors and found that those with lighter skin also had an altered form of the Kit ligand gene.

"It is the same genetic mechanism between organisms that are very different from each other," Kingsley said in a prepared statement.

The Kit ligand gene makes a protein that plays a role in maintaining the melanocyte skin cells that control pigmentation.

While this gene isn't the only factor that determines skin color, it does seem to account for about 20 percent of the pigmentation differences between people of African and European descent, Kingsley said.

The study is published in the Dec. 14 issue of the journal Cell.

More information

The PBS Web site has an article about differences in human skin color.

SOURCE: Stanford University, news release, Dec. 13, 2007