THE MUTATIONS PREVIOUSLY DESIGNATED AS FLIGHTLESS-I3, FLIGHTLESS-O2 AND STANDBY ARE MEMBERS OF THE W-2 LETHAL COMPLEMENTATION GROUP AT THE BASE OF THE X-CHROMOSOME OF DROSOPHILA-MELANOGASTER

By using a well defined panel of chromosomal deficiencies, duplications and lethals, we have mapped three mutations causing flightlessness, flightless-I3, flighlless-O2 and standby, to a single lethal complementation group (termed W-2) at the base of the X-chromosome of D. melanogaster. We also show that a fourth flightless mutation, termed grounded2, previously mapped near to the base of the X-chromosome, is distal to the cytogenetic interval 18F to 20F. Mutants homozygous for ihcflightless-I3 flightless-02 and standby mutations exhibit abnormalities of myofibrillar arrangements in the indirect flight muscles. They have distorted Z-bands and the myofibrils are often displaced from their normal parallel arrangement. These viable flightless mutations are all hypomorphs since the homozygous deficiency of the W-2 X-chromosomal region is lethal to the organism. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.