CYTOPLASMIC DYNEIN FUNCTION IS ESSENTIAL IN DROSOPHILA-MELANOGASTER

The microtubule motor cytoplasmic dynein has been implicated in a vari ety of intracellular transport processes. We previously identified and characterized the Drosophila gene Dhc64C, which encodes a cytoplasmic dynein heavy chain. To investigate the function of the cytoplasmic dy nein motor, we initiated a mutational analysis of the Dhc64C dynein ge ne. A small deletion that removes the chromosomal region containing th e heavy chain gene was used to isolate EMS-induced lethal mutations th at define at least eight essential genes in the region. Germline trans formation with a Dhc64C transgene rescued 16 mutant alleles in the sin gle complementation group that identifies the dynein heavy chain gene. All 16 alleles were hemizygous lethal, which demonstrates that the cy toplasmic dynein heavy chain gene Dhc64C is essential for Drosophila d evelopment. Furthermore, our failure to recover somatic clones of cell s homozygous for a Dhc64C mutation indicates that cytoplasmic dynein f unction is required for cell viability in several Drosophila tissues. The intragenic complementation of dynein alleles reveals multiple muta nt phenotypes including male and/or female sterility, bristle defects, and defects in eye development.