||FIG. 7. mRNAexpression of BMP-4 in the sensory organs of Xenopus laevis inner ear. (A) Longitudinal section through stage 45 inner ear shows
BMP-4 is expressed in the sensory organs. Anterior crista (ac), lateral crista (lc), posterior crista (pc), and maculae saccule (ms) display BMP-4 RNA
expression. Higher magnification of anterior crista is shown in (B), lateral crista in (C), and posterior crista in (E). (D) BMP-4 RNA is also expressed
in another sensory organ, macula utriculi (mu). (A–E) Arrows indicate BMP-4 expression. Lateral and posterior cristae have the strongest BMP-4
expression. Sensory organs consist of mechanoreceptors, the hair cells, and underlying cells called supporting cells. Based on the staining, it
appears that hair and supporting cells are labeled at least in the lateral and posterior cristae. In the remaining sensory organs, the staining was
too weak to be certain if hair cells were labeled. Anterior is to the top and lateral is to the left. Scale bar equal to 100 mm.