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Updated: Aug 22, 2026

Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Effects of G-protein mutations on skin color
Catherine D Van Raamsdonk1, Karen R Fitch, Helmut Fuchs
1Department of Genetics, Stanford University School of Medicine, Stanford, California 94305-5323, USA.
Abstract:
A new class of dominant dark skin (Dsk) mutations discovered in a screen of approximately 30,000 mice is caused by increased dermal melanin. We identified three of four such mutations as hypermorphic alleles of Gnaq and Gna11, which encode widely expressed Galphaq subunits, act in an additive and quantitative manner, and require Ednrb. Interactions between Gq and Kit receptor tyrosine kinase signaling can mediate coordinate or independent control of skin and hair color. Our results provide a mechanism that can explain several aspects of human pigmentary variation and show how polymorphism of essential proteins and signaling pathways can affect a single physiologic system.
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