Figure 5.

Presence of Yellow protein in third instar CNS neural cells is associated with adult male mating success. In all images, anti-Yellow antibody fluorescence is shown in red. Shown are fluorescent microscope (A, B, D–I) or confocal microscope (J and K) images of the third instar larval CNS. (A) Canton-S wild-type positive-control CNS, showing anti-Yellow staining in four CNS cells. (B) The y¹ loss-of-function negative-control CNS, showing no anti-Yellow staining. (C) Schematic of the third instar CNS, after Truman et al. (1993, their Figure 7), showing approximate locations of dividing neuroblasts at this developmental stage. The Yellow⁺ cells may be the four neuroblasts in red (see also Drapeau et al. 2003). (D–I) Shown are the CNSs from positive- and negative-control flies, and four hypomorphic y mutants, at higher magnification than that in A and B. (D) Canton-S CNS showing anti-Yellow cells. (E) y¹ CNS showing no anti-Yellow cells. (F) The y⁻⁸⁹³ mutant has moderately low MMS and no anti-Yellow cells in the CNS at this stage. (G) The y^−300gin mutant has normal MMS and normal anti-Yellow cells in the CNS at this stage. (H and I) Both y^3d and y⁻⁹¹ mutants have severely reduced MMS and no anti-Yellow cells in the CNS at this stage. (J and K) Confocal images of anti-Yellow cells from Canton-S positive-control flies, and the y^−300gin hypomorph whose males exhibit normal MMS. Yellow appears to be largely, if not completely, cytoplasmic in these cells.