The tracheal branching of l(2)38Ea66 embryos occurs normally with apparently normal cell number. At stage 17, the terminal branches show a variety of abnormal morphologies. One class of abnormalities is the duplication of terminal cells. The other classes show persistent filopodia formation in the dorsal side of the terminal cells and the ectopic accumulation of F actin dots, as well as the misorientation and bifurcation of the actin core and the terminal branch.
At low temperature and in uncrowded culture conditions, rare escaper ik25 adults (<1%) are observed, but they die shortly after eclosion. These escapers often exhibit abnormal bristles, both the interommatidial and the humeral bristles are affected. At high magnification, the actin footprints along the length of the bristle shaft in ik25 escaper adult eyes appears less organised than those in wild-type bristles. In wild-type, interommatidial bristles are found at alternating vertices, whereas in ik25 mutants these bristles are often duplicated at a single vertex and are misshapen and kinked.