AstC transcript is expressed in 4 DN1p neurons, 3 LP neurons, and -20 DN3 neurons. These neurons coexpress tim.

AstC transcript is observed in each larval brain lobe in two clusters of superior lateral protocerebral cells (3 and 7 cells), and three posterior medial protocerebral cells. AstC transcript is observed in a ventral lateral cell and ventral medial cell on each side of the larval subesophageal ganglion. In the larval ventral nerve cord, AstC transcript is observed in a pair of ventral lateral cells per thoracic hemisegment, a ventral medial cell in each mesothoracic hemisegment, a dorsal lateral cell in each abdominal hemisegment, and a dorsal medial and two ventral medial cells on each side of the posterior third of the abdominal ventral nerve cord. In each half of the adult brain, AstC transcript is observed in 7 superior medial protocerebral cells, 3 superior lateral protocerebral cells, 7 posterior medial protocerebral cells, a posterior lateral protocerebral cell, 3 ventral lateral subesophageal cells, 4 ventral medial subesophageal cells, 5 anterior dorsal optic lobe cells, and a posterior ventral optic lobe cell. AstC transcript is also expressed in many cells in the adult midgut, with the greatest density in the middle of the midgut.

AstC protein is expressed in 4 DN1p neurons, 3 LP neurons, and ~20 DN3 neurons; these neurons coexpress tim. AstC protein cycles in DN1p neurons, and accumulate at higher levels during the dark phase.

AstC peptides were detected in extracts from adult and larval midguts.

About 20 AstC immunoreactive cells are found just after the restriction separating the iron cells from the posterior midgut. A larger number are found in the first half of the posterior midgut. These do not overlap with the AstA expressing cells in the posterior region of the posterior midgut. A small number of staining cells are found in the copper cell region of the middle midgut.

AstC immunoreactivity is observed in two medial cells in the superior protocerebrum that send processes laterally along the anterior of the superior protocerebrum to impinge on cells in the medial protocerebrum, and posteriorly through the subesophageal ganglion to the posterior end of ventral nerve cord. Immunoreactivity is also observed in 8 cell bodies of the lateral protocerebrum. Two to three faintly stained cells in the medial protocerebrum appear to be the cells impinged upon by the superior protocerebral cells; these cells extend axons posteriorly to the ventral nerve cord, and do not contact any other immunoreactive cells. There is one large intensely stained medial cell body in the subesophageal ganglion, and 4-5 smaller less intensely stained more lateral cell bodies in the ventral nerve cord. One immunoreactive cell per thoracic ganglion extend processes to the end of the ventral nerve cord. There are several small lateral cells in the abdominal ganglia.