D transcripts are detected in the nurse cells and the ooctye in stage 6 of oogenesis while the protein is only seen in the oocyte.

The D transcript is first detected in embryonic cycle 13 as a wide band from 15-65% egg length. At cycle 14, the band splits into two domains at 15-30% egg length and about 50% egg length. Procephalic expression is detected at cycle 14. In the cellular blastoderm embryo, D transcript is expressed in 7 irregular stripes, as well as in a dorsal saddle pattern. During gastrulation and germ band extension, two 4-cell wide rows of ventral neurectoderm flanking the invaginating mesoderm, as well as procephalic neurectoderm, express D transcript. During germ band retraction, D is expressed in a subset of cells in the brain, the ventral nerve cord, the hindgut, and segmentally repeated stripes of cells along the ventral epidermis.

D transcript is not detected before nuclear cycle 10 of embryogenesis. In early stage 4 embryos, D transcript is present in a wide central domain, and in late stage 4, it is also present in an anterior domain. The central domain begins to split in early stage 5, and seven stripes are visible by late stage 5. The 6 anterior stripes and the anterior domain expression subsequently disappear. In late stage 6 to early stage 7, neurectodermal expression appears, first as 14 stripes, then expanding to a continuous longitudinal band along the germ band.

D-protein expression can be found in the distal part of the inner proliferation zone in the larval optic anlage and in the larval medulla anlage.

D protein labels three paired clusters of cells in the adult brain: one in the protocerebrum, another near the optic lobe border and a third lateral to each antennal lobe (LAAL), which contains around 225 neurons. Subsets of these LAAL neurons co-express ScerGAL4^ChAT.7.4 or ScerGAL4^Gad1.3.098, identifying them as cholinergic or GABAergic, respectively. They do not co-express olfactory projection neuron markers such as ScerGAL4^GH146, ScerGAL4^acj6-PG63, ScerGAL4^NP6115 or ScerGAL4^Mz699. A significant proportion of LAAL neurons correspond to olfactory local neurons, as identified by the expression of ScerGAL4^KL107, ScerGAL4^c305a, ScerGAL4^NP1227 and ScerGAL4^Sxl-NP2426. D protein is also expressed in ring neurons R2 and R4, which co-express ScerGAL4^c547, and in three midline neuron clusters in the thoracic-abdominal ganglion.

D-protein is expressed in medial neuroblasts of the developing larval medulla. A subset of these neuroblasts co-express slp1- and slp2-protein. D-protein is detected in a small number of ganglion mother cells in the medulla anlage.

l(1)sc-protein is expressed in around two rows of neuroepithelial cells at the border of the developing larval medulla.

vvl-protein is expressed in newly formed larval medulla neurons.

run-protein is expressed in newly formed larval medulla neurons.

SoxN protein and D protein were shown to co-localize in the ventral epidermis from stage 12 until the end of embryogenesis.

D is first detected in the presumptive oocyte in region IIb of the germarium. From oogenesis stages 2-7, it is detected specifically in the oocyte cytoplasm and not in nurse cells or follicle cells. It is not detected from stage 8 on.