Developmental analysis of a newly isolated sex-linked wing mutation, umbrella (uba), causing pattern deficiency in Drosophila melanogaster.

Abstract

A new temperature-sensitive pattern deficient mutation, umbrella (uba) (1-43.9±1.6) is described. This mutation causes pleiotropy and phenotypic variation in malformed wing margins and veins at 25°C. The temperature-sensitive period was during the late half of the third larval stage (96 to 120 hr after egg laying at 25°C). Aldehyde oxidase activity decreased in the presumptive wing margin and anterior compartment of the presumptive wing blades. Cell death, expressed disc-autonomously, occurred from the early third instar and became prominent in presumptive wing blade regions at the mid-third instar. The number of wing disc cells decreased to 68% and 78% those of the wild-type at the mid- and late third instars, respectively. Consequently, the pattern abnormalities of uba flies can be ascribed to localized disc cell death. The relationships between uba and other wing mutations causing pattern abnormalities are discussed.