抄録
Phenotypic expressions of a mutant unextended (uex, 2-55) of Drosophila melanogaster were examined. Four major morphological abnormalities are associated with this mutant; (1) unexpanded wings, (2) insufficiently extended third legs, (3) vertically oriented postscutellars and indented posterior end of scutellum, and (4) broad thorax-abdomen junction. It was noted that all these abnormalities are reminiscent of normal pharate adult morphology. High temperature treatment was effective, though to a limited degree, to expand the wings if given on the second day after pupariation. Mechanical pressure was found to remedy the wing abnormality but not others. A possibility that the abnormal timing in cuticle hardening following eclosion might cause all the abnormalities is discussed.