ScerGAL4C855a drives expression from the end of the first instar onwards in the neuroepithelial cells of the outer optic anlage (OPC), as well as in some cells in the central brain and the ventral nerve cord.
In third instar larva, expression in wing and haltere discs most pronounced in pouch region. In ovary expressed in all follicle cells overlying oocyte, starting at stage S9.