Sex-specific expression patterns of dsx in sectioned A. aegypti pupal brains. The detailed expression pattern of dsx was analyzed through in situ hybridization experiments (using the dsx common probe) that were performed following preparation of paraffin sections of female (A-C) and male (D-F) heads. Twelve micron sections through different portions of the brain reveal the following structures, which are shown in brain hemisegments oriented dorsal upward in (A-F): antennal lobe (al), lamina (la), and medulla (me). Expression of dsx is detected in the visual system of both females and males (blue arrowheads in A, B, D, E). However, dsx is dimorphically expressed in the antennal lobe (highlighted by red dots in C, F) and the mushroom bodies (red arrowheads in A, D) of females and males. Hybridizations with a sense control probe detected no signal in comparable brain sections (not shown). These data are consistent with the results presented in Figure 10.