Expression of genes involved in endolymph homeostasis in the lau mutant ear. (A-D) The endolymphatic duct, marked by expression of bmp4 (arrowheads, A,B) and foxi1 (C,D), appears to develop normally in lau mutants. The three cristae also express bmp4 normally (asterisks, A,B). (E-J) Expression of ion transporter genes in the lau mutant ear. (E,F) Expression of the atp1a1a.4 subunit of Na+/K+-ATPase1 is more diffuse and lacking from the ventral pillar (vp). (G-J) There is a substantial reduction in both kcnq1 and nkcc1 expression. Abbreviation: vp, ventral pillar (E) or ventral projection (F). Alleles: B,D,H,J, tk256a; F, tb233c. Scale bars: 50 μm.