scrt is first expressed in the embryo in S1 neuroblasts. It is expressed in most cells of the CNS by stage 12, with the strongest expression in a group of 5-7 cells per abdominal hemisegment arranged in a crescent.

The scrt transcript is expressed in neuronal precursor cells. In northern blots, the 6.5 kb scrt transcript is detected in 4-12 hour embryos, but not in 0-4 hour embryos. By in situ hybridization, scrt transcript is detected at stage 8 in a single row of ectodermal cells flanking the ventral midline. These cells then delaminate and contribute to the first three rows of stage 1 neuroblasts in the central nervous system. Subsequently, all stage 1 neuroblasts and then later neuroblasts, express scrt. The ganglion mother cells and postmitotic neurons also express scrt. In the peripheral nervous system, scrt is expressed first in the sensory mother cells, then in secondary precursor cells, and finally in postmitotic neurons. In third instar larvae, scrt is expressed in neuronal cells of the wing disc, in cells posterior to the morphogenetic furrow of eye-antennal discs, in neuronal precursor cells in the leg disc, and in many cells in the brain and the ventral nerve cord. scrt transcript is also detected in developing neurons of the pupal wing.