A SCREEN FOR LETHAL MUTATIONS IN THE CHROMOSOMAL REGION 59AB SUGGESTSTHAT BELLWETHER ENCODES THE ALPHA-SUBUNIT OF THE MITOCHONDRIAL ATP SYNTHASE IN DROSOPHILA-MELANOGASTER

We report the isolation and complementation mapping of lethal mutation s within the 59AB region on the second chromosome of Drosophila melano gaster. The newly induced lethal mutations in this region define four different complementation groups. Using existing and newly induced def iciencies, these loci can be assigned to three different chromosomal i ntervals. Moreover, complementation analysis with chromosomes carrying various P element insertions, in combination with a molecular charact erization of the corresponding insertion sites, suggests that the prev iously described male sterile mutation bellwether is an allele of an e ssential gene that encodes the alpha subunit of the mitochondrial ATP synthase.