FIGURE 3

FIGURE 3

Olfactory rod cells are present in the olfactory epithelia of ift88^–/– zebrafish mutants, which lack cilia. (A,B) Maximum intensity projections of Airyscan confocal images of phalloidin stains of a 5 dpf wild-type (A) and ift88^–/– mutant (B) larva; dorsal views, anterior to the top. Grayscale values from the original fluorescence image have been inverted. Abbreviations: nm, cranial neuromast; op, olfactory pit. Several olfactory rods (arrowheads mark examples) are visible in each olfactory pit. Scale bar = 50 μm. (C) SEM of the head of a 4 dpf wild-type larva. Scale bar = 100 μm. (D,E) SEM of 4 dpf larval wild-type olfactory pits [enlarged from panel (C)]. Scale bars = 10 μm. Insert in panel (D) shows enlarged view of boxed area in panel (D). Arrowhead marks the tip of an olfactory rod cell apical projection surrounded by olfactory cilia. (E′) Enlarged view of boxed area in panel (E). Arrowhead marks one olfactory rod. Scale bar = 5 μm. (E″) Enlargement of olfactory rod in panel (E′) (arrowhead). Scale bar = 1 μm. (F) Frontal view SEM of the head of a 4 dpf ift88^–/– mutant larva. Scale bar = 100 μm. (G) A map of the positions of olfactory rod cell projection emergence through the OE in ift88^–/– mutant larvae (N of olfactory pits = 3), based on SEM images at 4 dpf; anterior “A” to the top, lateral “L” to the right. One dot represents one olfactory rod. Different coloured dots represent olfactory rods from different larvae. (Compare with Figure 1E). (H) SEM of 4 dpf larval ift88^–/– mutant olfactory pit [enlarged from panel (F)]. Scale bar = 10 μm. (H′) Enlarged view of boxed area in panel (H). Arrowhead marks one example olfactory rod cell projection present despite the loss of cilia. Scale bar = 5 μm. (I) Enlarged SEM of olfactory rods (arrowhead marks example) in 4 dpf larval ift88^–/– mutant olfactory pit (from a different individual). Scale bar = 1 μm.