A: Prosensory domains are labeled by Fzd1 expression including the prosensory saccule (asterisk)/basilar papilla patch on the medial side and utricular macula (UM) laterally. B,C: Complementary expression patterns of two Wnt inhibitors, Frzb and SFRP2 (asterisk, prosensory saccule; bar, prosensory utricle; BP, prosensory basilar papilla). D,E: Broad otic expression of Fzd9 and Dkk1. F: Exclusive expression of Fzd10 in the distal-abneural BP primordium. G: Nonsensory lateral wall of the cochlear duct (nsCD, demarcated by black line) transcribing Wnt6. H: Lateral ampulla expresses Wnt5a. (Arrow head in B and G indicate weak transcription of Frzb and Wnt6, respectively in the same region). I: Ventral tip of the cochlear duct labeled by locally restricted expression of Wnt11. J: Endolymphatic sac and duct express Wnt3a. K: Wnt5b expression in the anterior crista (AC) region at s25. L,L inset: Weak Wnt7a transcription in the primordia of the auditory BP and vestibular lagena macula (LM) at s25. M: Nonsensory expression of Wnt7a at s30. Transcripts border the saccular macula (SacM) and flank the BP but are not present in the prosensory domains. N: At s25 the BP primordium is expressing Wnt9a, shown in cross section (neural is to the left). The neural side of the forming cochlear duct also shows some Wnt9a transcription. O: At s27 the neural side of the cochlear duct, the prospective homogene cell domain, expresses Wnt9a, flanking the BP domain. P: Wnt3 transcripts label the endolymphatic sac and duct but are not present in the ventral medial domain (bar) at s23. Abbreviations: AC, anterior crista; Amp, semicircular canal ampulla; BP, basilar papilla; D, dorsal; Esac, endolymphatic sac; HB, hindbrain; L, lateral; LM, lagenar macula; M, medial; nsCD, nonsensory cochlear duct; P, posterior; s, embryonic stage; SAG, statoacoustic ganglion; SacM, saccular macula, UM, utricular macula. In situ hybridization signals (purple) are counterstained by axon labeling with 3A10 antibody (brown) in F. Scale bar =100μm.