| |
Fig. 1. Small secretory cells (SSCs) in the Xenopus tadpole epidermis. (A) Stage 33 tadpole stained for serotonin (red) and cilia (green) using anti-serotonin and anti-acetylated-α-tubulin antibodies. (A′,A′) Higher magnification reveals vesicular nature of serotonin staining. Please note a serotonin-positive vesicle attached to cilia (white arrowhead in A′). (B) Localization of serotonin-containing vesicles in SSCs. Cell boundaries marked by actin staining using phalloidin. Higher magnifications (left panels in B′-B′′) and orthogonal projection of z-stack slices (white dashed lines; right panels in B′-B′′) demonstrate serotonin-positive vesicles beneath, at, or above the apical cell membrane (B′-B′′, green arrowheads). (C) SEM of stage 32 tadpole displaying MCCs and SSCs. (C′) Higher magnification of two SSCs. Red arrowheads highlight detaching vesicles. Scale bars: 50 μm in A′; 10 μm in A′; 5 μm in B-B′′; 20 μm in C; 5 μm in C′. |
