<i>dVMAT</i> mutants show decreased histamine labeling in subretinal glia.

<p>(A–G) Confocal projection images of whole-mount preparations of retina and optic lobes in control <i>w</i> (A–D) and mutant <i>dVMAT</i>^Δ14 homozygotes (E–G). Tangential views are shown in (A,C,D,F,G); the surface of the lamina is shown in (B) and (E). In <i>w</i> tissues, a primary antiserum to histamine shows labeling of the retina (A) (arrowheads), the distal lamina (arrows) and nerve terminals in the medulla (asterisks). <i>dVMAT</i>^Δ14 mutants (E–G) show reduced labeling at the surface of the lamina (E) (arrows) and retina (F) (arrowheads) relative to the lamina (B) and retina (C) in <i>w</i>. Labeling of nerve terminals in the medulla (D,G) (asterisks) and an area near the optic chiasm (D,G) (small arrow) in the <i>dVMAT</i> mutant (G) is less prominently reduced relative to the <i>w</i> control (D). (H) Cryostat sections of a <i>w</i> head labeled with the anti-histamine antibody also show labeling of the lamina, including a band just beneath the retina (H) (large arrows) as well as processes in the medulla (asterisks). Note that labeling of the retina is less evident in these cryostat sections compared with that in the confocal stacks shown in (A–G). (I) <i>dVMAT</i>^Δ14 shows a decrease in labeling in the distal lamina relative to <i>w—</i>compare (H) and (I) (large arrows). Labeling in the medulla (asterisks) is less reduced in <i>dVMAT</i>^Δ14 and is strong in the proximal lamina (small arrow). Bars: (A) 50 microns, (B–G) 25 microns, (H,I) 50 microns.