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Fig. 3
The proneural transcription factor gene Neurod4 is expressed in ampullary organs but not neuromasts.
(A–F) In situ hybridization for Neurod4 at stages 29 (A), 39 (B), 41 (C) 43 (D) and 46 (E). At the earliest stages, transcripts are observed in the olfactory epithelium, eye, trigeminal ganglion. By stage 39 transcripts are observed in the developing ampullary organ fields of the operculum, rapidly expanding to other ampullary organ fields in older embryos. Expression is limited to ampullary organs and is not observed at any stage in neuromasts, as clearly seen at higher power at stage 46 (F). Dotted lines indicate approximate boundaries of neuromast canal lines. (G–I) Potential Neurod4 interactors Pou4f1 (G), Lhx3 (H) and Myt1 (I) are expressed in both ampullary organs and neuromasts. Abbreviations: ao, ampullary organ; e, eye; nm, neuromast; olf, olfactory epithelium; ov, otic vesicle; tg, trigeminal ganglion. Scale bars: A-F, 200 µm; G-I, 100 µm.