The other cells expressing high levels of smid are in the gonads , which show expression through to hatching and into larval life. Expression of smid in the non-neurogenic ectoderm decreases markedly post stage 12, coincident with the final divisions of the epidermal cells. The GAL4-induced lacZ expression of line C161 was examined. Line C161 contains a P-element inserted into the smallminded gene. At early larval stages, lacZ is expressed in neuroblasts and in sensory neurons.
Neuroblast expression is seen in the cephalic and thoracic neuromeres of the central nervous system.
Expression is also seen in imaginal discs . In larvae, smid expression is again detected in NBs as they begin their post-embryonic program of cell division. By 96 h after hatching, smid is expressed at high levels throughout the cephalic and thoracic neuromeres and in small segmentally repeated sets in the abdominal neuromeres. During late larval stages, high smid expression is detected in small clusters of cells associated with muscles and sensory neurons. The CNS of wild-type and homozygous C161 larvae are comparable in size and indistinguishable.