Isolation of a Drosophila melanogaster desiccation resistant mutant.

Mutagenesis provides a powerful way of isolating genetic and physiological processes underlying complex traits, but this approach has rarely been applied to investigating water balance in insects. Here, we describe the isolation of a desiccation-resistant mutant of Drosophila melanogaster. Mutagenesis of a desiccation sensitive line resulted in the isolation of a mutant with two-fold higher resistance. The mutant was partially dominant and mapped to the second chromosome. Mutant flies showed lower rates of water loss, and had a higher water content, but showed no change in body mass, glycogen content, hemolymph volume or water content tolerated at death from desiccation. These physiological differences are contrasted to changes in lines of D. melanogaster mass selected for altered stress resistance. Isolation of this mutant provides an opportunity to identify a gene involved in water balance in insects.