Expression of extracellular matrix (ECM) genes and other semicircular canal markers is altered in the lauscher mutant ear. (A-JJ) Expression of ECM structural and enzyme genes in lau mutant ears at 76 hpf, 4 dpf and 5 dpf. Expression of the HA binding hapln1a (A-F) and the versican genes vcana and vcanb (M-X) is highly upregulated in mutant canal tissue. Expression of hapln3 is normally upregulated in wild-type ears on canal projection fusion (G,I,K); in the mutant, fusion fails, and transcript levels remain low (H,J,L). Antibody staining for type II Collagen (Y-DD) shows precocious protein accumulation at 76 hpf in mutants (Y,Z), persisting at 4-5 dpf (AA-DD); aberrant canal tissue is visible. Genes coding for enzymes for chondroitin synthesis (chsy1, EE,FF) and HA production (has3, GG,HH; ugdh, II,JJ) are upregulated in mutants at 76 hpf. (KK-PP) The canal markers aldh1a3, bmp7b and sox9b are upregulated in the unfused projections in the lau mutant ear. wt, wild type; sib, phenotypically wild-type sibling. Mutant alleles are shown on the panels. Scale bars: in A, 50 μm (applies to columns 1 and 2); in C, 50 μm (applies to all other panels).
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