In flight muscles of recently eclosed adults myofibrils are missing. Thick and thin filaments are present in the sarcoplasm though normal Z discs are not evident.
Flies are flightless and hold their wings in an abnormal position, and sometimes show variable jump ability.
Mhc7, wupAhdp-4 has striated muscle thin filament phenotype
Z disc morphology is improved in the double mutant with Mhc7. Thin filaments are reduced, even in the absence of myosin.