When weeScer\UAS.cPa is driven by Scer\GAL4neur-P72 in stgAR2 animals exhibit severe bristle loss. The lineage of external sensory organ is significantly modified in mutants. Usually, only two cell divisions of the pI cell are seen as opposed to the three seen in wild-type. The first mitosis, oriented in the epithelial plane, gives rise to a large anterior cell and a small posterior glial cell. The glial cell quickly undergoes nuclear fragmentation. The large anterior cell divides once and resulting in a sheath and neuron cell. Also the timing of cell divisions is stringly affected. In the median rows od sensory organs, the first division occurs on average 4 hours later than in wild-type. The second division occurs ~3 hours late. Finally the polarity of the first division is reversed compared to the wild-type situation. This abnormal division sequence is observed in 78% of mutant organs.