Figure 9. dsx^GAL4 is expressed in neurons with sexually dimorphic projections.

dsx^GAL4 expression in the brains and VNCs of peri-eclosion males (XY) and females (XX) visualized with UAS-mCD8::GFP membrane-bound GFP reporter (green) and counterstained with DN-Cadherin (magenta). Confocal projections of brain and VNC sections are shown: anterior (ant), central (cen), posterior (post), dorsal (dor), and ventral (ven). For each panel, brains are in the left column and VNCs are in the right column. (XY) In the male anterior brain, projections from dsx^GAL4-expressing neurons project through the anterior dorsal commissure (arrow), and there is expression in aDN neurons (barbed arrow) as well as putative glia on the anterior cortex in the anteroventral optic cleft (arrowhead). In the central brain, dsx^GAL4-expressing neurons innervate the dorsofrontal cortex (DFC, arrow), the peripeduncular neuropile (PPN, barbed arrow), and the ventrolateral protocerebrum (VLPR, arrowhead). In the posterior brain, clusters of dsx^GAL4-expressing cells are found, as described in Figure 7. In the ventral VNC, projections of foreleg gustatory neurons are visible crossing the VNC midline (arrow), while in the dorsal VNC, projections are seen in midline and lateral tracts (arrows), and there is an arborization in the dorsal metathoracic neuropile (arrowhead). Extensive expression is also seen in the abdominal ganglion (brackets, dor and ven). (XX) In the female brain, the dsx^GAL4 expression pattern is similar to that of males but with several differences. In the anterior brain, there are no projections through the anterior dorsal commissure. Putative glia were seen as in males (arrowhead). In the central brain, expression in the DFC (black-outlined arrow), PPN (barbed arrow), and VLPR (arrowhead) is reduced relative to males. In the posterior brain, there is a dramatic reduction in the number of neurons relative to males. In the VNC, there is expression in the abdominal ganglion but not the thoracic cell bodies. The dorsal metathoracic arborization is still visible (arrowhead, ven), as are medial and lateral tracts (arrows, dor). Prothoracic gustatory projections are visible (arrow, ven) but do not cross the midline.