LAUSR

Abstract A yellow-bodied male appeared spontaneously in an isofemale line of Drosophila nappae established from a wild-caught female collected at the Forest Reserve of the Instituto de Biociencias da Universidade de Sao Paulo, Cidade Universitaria “Armando de Salles Oliveira”, Sao Paulo city, state of Sao Paulo, Brazil. This is the first mutation found in D. nappae, a species belonging to the tripunctata group. The yellow male was isolated and individually crossed to two wild-type (brown-colored) virgin females from the same generation, yielding numerous offspring. All F1 individuals were wild-type, but the phenotypes yielded in the F2 generation were wild-type females, and both wild-type and yellow-bodied males. The latter yellow male mutants backcrossed with virgin wild-type F1 females yielded four phenotypes (brown-colored and yellow-colored flies of both sexes), indicating an inheritance pattern of X-linked recessive. Chi-square goodness of fit tests (α = 5%) detected no significant differences among the number of flies per phenotype. The new mutation is hereby named yellow, due to its probable homology to a similar mutation with an identical inheritance pattern found in Drosophila melanogaster.