Fig. 2

Developmental expression of zebrafish omp-1 (zomp-1) and otolin-1 (zotolin-1). zomp-1 in situ hybridization at 14-somite stage (A) and 24 hpf (B). zomp-1 transcripts are detected only in the otic vesicles (arrowheads). (C) Magnification of the otic vesicle at 24 hpf. zomp-1 expression is more intense in the ventro-posterior part (arrowhead). (D) zomp-1 in situ hybridization at 72 hpf. The expression level of zomp-1 is lower at the anterior and posterior maculae (am and pm, outlined by dotted lines) than in the non-sensory parts of the epithelium (arrowheads). A dotted line indicates the outline of the otic vesicle. (E) Otic vesicle of a 26-somite embryo labeled with an anti-OMP-1 antibody. Both otoliths are slightly labeled. (F) At 35 hpf, both otoliths are heavily stained with the anti-OMP-1 antibody. The ventro-lateral epithelium posterior to the anterior macula is also labeled (arrowhead). (G–I) zotolin-1 in situ hybridization at 72 hpf; three increasingly deeper focal planes of the same ear; zotolin-1 transcripts are not detected in the anterior (G) nor in the posterior macula (H), but at the dorsal and ventral sides of the latter (I, arrowheads); am, anterior macula; pm, posterior macula. In panels (E) and (F), two photos at different focal planes are juxtaposed for focusing the two otoliths. All panels show lateral views, anterior to the left, dorsal to the top. Scale bar in (C) indicates 25 μm in panels (C) to (I).