, First Identified in in 1910, Is Encoded by the Arylalkalamine N-Acetyltransferase (AANAT1) Gene.

The pigmentation mutation is a commonly used recombination marker characterized by a darkly pigmented region at the wing hinge. Identified in 1910 by Thomas Hunt Morgan, was characterized by Sturtevant as the most "workable" mutant in the rightmost region of the second chromosome and eventually localized to 2-107.0 and 60C1-2. Though the first mutation was isolated over 110 years ago, is still not associated with any gene. Here, as part of an undergraduate-led research effort, we show that is encoded by the () gene. Both alleles from the Morgan lab contain a retrotransposon in exon 1 of the RB transcript of the gene. We have also identified a new insertion allele and generated multiple deletion alleles in that all give a strong phenotype. In addition, expression of RNAi constructs either ubiquitously or in the dorsal portion of the developing wing generates a similar phenotype. We find that alleles have additional phenotypes, including ectopic pigmentation in the posterior pupal case, leg joints, cuticular sutures and overall body color. We propose that the acetylated dopamine generated by decreases the dopamine pool available for melanin production. When function is decreased, the excess dopamine enters the melanin pathway to generate the phenotype.