In most mutant clones in the pIIb cells of the sensory organ precursor lineage, the spindle is orientated within the plane of the epithelium (in contrast to the apical-basal orientation in the wild type) and the spindle shows a clear bias along the anterior-posterior axis. There is no effect on spindle positioning in the pI cell division.
In mutant embryos the DA3A muscle is duplicated at the expense of DO5A in most segments.
Additional dorsal oblique muscles are seen in homozygous embryos.
