TALE-class homeodomain transcription factors, homothorax and extradenticle, control dendritic and axonal targeting of olfactory projection neurons in the Drosophila brain

► We show that Homothorax is expressed in Drosophila olfactory projection neurons. ► hth is essential for correct axodendritic targeting of the olfactory PNs. ► Another homeodomain factor, Exd, is coexpressed with Hth in the olfactory PNs. ► exd is also required for correct axodendritic targeting of the olfactory PNs. ► Hth and Exd positively regulate each other expression in the olfactory PNs.