Genetics. Zebrafish researchers hook gene for human skin color.

Biology 321 This article reflects important themes that we will explore in this course: • The value of studying model organisms • The molecular basis of allelic variation and how it affects phenotype • In complex traits, allelic variation in more than one gene underlies phenotypic variation • Allele frequencies vary with the population under consideration • The genetic control of many traits is not yet fully understood • The complicated & confusing business of gene names. Genes are often named for the phenotype produced by a mutation in the gene: the golden mutation in zebrafish defined the golden gene; the equivalent gene in humans, though, was named for the protein it specifies: SLC24A5 = solute carrier family 24, member 5. ********************** GENETICS: Science 310: 1754 2005 Zebrafish Researchers Hook Gene for Human Skin Color Michael Balter People come in many different hues, from black to brown to white and shades in between. The chief determinant of skin color is the pigment melanin, which protects against ultraviolet rays and is found in cellular organelles called melanosomes. But the genetics behind this spectrum of skin colors have remained enigmatic. Now, on page 1782 of this week's (12/16/05) issue of Science, an international team reports the identification of a zebrafish pigmentation gene and its human counterpart, which apparently accounts for a significant part of the difference between African and European skin tones. One variant of the gene seems to have undergone strong natural selection for lighter skin in Europeans.