Fig 7. Proposed gene network and timeline for the acquisition of anterior identity in the zebrafish otic vesicle.

(A) Proposed gene regulatory network. (B) Schematic timeline showing sequential onset of expression of anterior markers in the zebrafish otic placode and vesicle. Diagrams in A and B are based on the results of this study, together with previously published data [2–6, 9, 11, 12, 28]. Abbreviations: Fgf_e, extrinsic Fgf protein; fgf_i, intrinsic (otic vesicle) fgf gene expression; Hh_e, extrinsic Hedgehog protein; hpf, hours post fertilisation; ss, somite stage.