Zebra fish and skin pigmentation
Scientists have found up to 100 genes responsible for variation in the skin color. And research conducted on zebra fish is shedding some light on the mystery of our own skin color. Humans and fish have similar pigment cells, containing pigment granules called melanosomes. Differences in the number, size and nature of these determine the many different shades of skin color. For example, Europeans have fewer, smaller and lighter melanosomes than those from people of West Africa.
In 2005 scientists from Pennsylvania State University College of Medicine in Hershey, Pa., found that the zebra fish variant called "golden" also had fewer, smaller and less heavily pigmented melanosomes than normal zebra fish. The dark stripes on these fish are caused by melanin, the same pigment in humans. The golden variety is lighter than normal zebra fish and the scientists found that this was due to a single mutation on SLC24A5. When the scientists introduced the human version of the gene into the golden zebra fish they observed that the dark stripes appeared, and the fish were no longer golden.
So what does this have to do with human skin color? In humans 93% of Africans, Native Americans, and East Asians had the original version of the gene, but most European-American people (about 98%) had the version with the single genetic mutation.