is first detected at 15 hours after the second to third instar larval transition where it is observed in a single bristle sensory organ precursor (SOP) in the notum. At 20 hours it is expressed in the SOP of the wing hinge chordotonal organ and in a few more bristle SOPs in the wing and notal regions. By 30 hours it is upregulated in two stripes of triple-row SOPs at the wing margin and in a number of newly differentiated bristle SOPs in the wing and notum.
is a predominantly nuclear protein. The only reported exception is in the wing disc, in the ectodermal cells surrounding the presumptive SOPs, where expression is not confined to the nuclei.
is a nuclear protein whose expression is limited to precursors and early differentiating cells of the PNS. sens
protein and transcript expression patterns are similar. Expression is mainly detected in proneural fields of some SOPs, nuclei of SOPs, and differentiating cells of the PNS. sens
protein is first detected at stage 10, peaks at stages 11 and 12, and starts disappearing by stage 13. Expression was also studied in imaginal discs. sens
protein is expressed in eye-antennal discs in the R8 photoreceptors, two clusters of cells in the lateral portion of the disc, and the chordotonal organs of Johnston organs. In leg discs, expression is detected in the femoral chordotonal organ, and other external sensory SOPs. In wing discs, sens
expression is dynamic, with expression first detected in ectodermal cells surrounding presumptive SOPs. The presumptive SOPs subsequently accumulate higher levels of sens
protein. Comparison of sens
protein expression in wild-type discs indicates that the expression of the two proteins do not overlap significantly.