dpp reporter is barely expressed in anterior and posterior dorsal nests histoblasts at 4-6h APF and not at all in surrounding LECs. Only a small group of cells in the ventral nest begin to express at this stage. During the onset of histoblast expansion (16-17h APF), dpp-LacZ is expressed in discrete dorsal cells from the anterior dorsal and ventral nest. In addition, dpp reporter is upregulated in most larval epidermal cells surrounding each of the four nests.
In addtion to expression anterior to and close to the A/P boundary of third instar wing discs, dpp reporter expression is observed in a proximal region of the posterior compartment beginning in the mid-third-instar larval stage. In the adult wing, staining is observed along the A/P border and in the axillary cord but not in the alula.
In embryo, expression in anterior spiracles and in PNS not certain.