is specifically expressed in all primary photoreceptor neuron precursors (Bolwig organ primordium) in a short highly dynamic pulse during embryonic stages 11 and 12. Expression is initiated first in two primary precursors at mid stage 11, and is subsequently upregulated in the remaining two primary precursors. Expression of sens
ceases during mid-late stage 12, when they start to express salm
, and is then maintained until their maturation into fully differentiated Rh5
-positive photoreceptors. By stage 15, no sens
staining can be seen in salm
are detected in sensory precursor cells earlier than the rho
reporter. All three are co-expressed in SOP cells of slightly older embryos. sens
expression begins to fade in the C1 SOP cell lineage in stage 12.
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.