Fig. 3

Basal blebbing in synj1^Q296X hair cells occurs near synaptic ribbons and is Ca²⁺-dependent.

FM 1–43 labeling of wild-type (A) and synj1^Q296X (B) neuromast hair cells. Note the bleb or membrane protrusion at the base of a mutant cell (arrow). Single optical sections of membrane-targeted EGFP (Tg(brn3c:mgfp)) expressed in wild-type (C) and mutant (F) hair cells. D, G) Ribeye-b immunolabel (red staining) of the same neuromasts, indicating ribbons. E, H) Overlays of membrane-targeted EGFP and Ribeye-b label. Arrows in panel H indicate blebs near the ribbon in mutant hair cells. I) Basal blebbing was Ca²⁺-dependent. Blebbing occurred minimally in neuromast hair-cells of wild-type larvae (black bar). In contrast, blebbing was significantly increased in synj1^Q296X mutant hair cells (grey bar). Blebbing was minimal in cav1.3^R1250X mutant hair cells (blue bar), as well as cav1.3^R1250X/synj1^Q296X double mutant hair cells (blue stripe bar). Blebbing still occurred in synj1^Q296X mutants that were transduction-deficient by morpholino-mediated cadherin23 knockdown (grey stripe bar). Numbers in parentheses above bars indicate number of hair cells examined. Scale bars, 3 μm.