Accurately reflects expression of ap in terms of cells in which that gene is expressed; however, the ap protein is nuclear, whereas this reporter is targeted to microtubules and thus labels cell bodies and axons. In embryonic VNC, expresssion restricted to 7 cells (interneurons) in each thoracic hemisphere.

Analysis of BtauMAPT^{ap.C.T:EcollacZ}expression suggests that ap-expressing cells are interneurons that startto elongate axons soon after they begin expressing ap protein.