Fig 1

taz^-/- mutants show midline separation defects.

(A) Predicted transcripts of wild-type (top) and the TALEN generated taz^ua1015 mutant allele (bottom). The zebrafish taz^ua1015 mutant allele contains a 29 bp deletion, 25 bp downstream from the start codon, which results in a frameshift mutation and loss of all functional domains. (B) Microscopic analysis of embryonic phenotypes. Wild-type (top) and taz-/- mutant embryos (bottom) were analyzed at 24 hpf, shown at both lateral and dorsal views. Consistently, taz-/- mutants display disruptions to hindbrain morphology (lateral view, arrowhead) as well as failure of the brain ventricle midline separation (dorsal view, arrowhead). (C) atoh1a in situ hybridization on wild-type and taz-/- mutant embryos from 22-36 hpf were performed to visualize ventricle perturbations over the course of development. (D) Texas Red Dextran injections were performed into the ventricle of wild-type and taz-/- mutant embryos at 24 hpf to visualize extent of ventricle defects in live animals. Scale bar =  100 µm.