Fig. S2

Together, zebrafish six1a and six1b are required for normal MMP-derived muscles and ear sensory epithelia. (A-D) Confocal projection of 120 hpf phalloidin-labeled embryos, imaged ventrally. Muscles appear normal in wild-type and single mutant embryos, but the SHM (red) is shortened and the AbFM (brown) is sometimes absent in six1a;six1b double mutants. In A-H, Muscles are false-colored as described in Figures 1 and S1. (E-P) Confocal projection of fixed 76 hpf six1b:lyn-GFP transgenic embryos, imaged laterally. (E-H) MMP-derived hypaxial muscles are normal in wild-type and single mutant embryos, but are reduced in six1a;six1b double mutants, which often lack the AbFM (brown) which normally covers the AdFM (yellow) (E-H). Trunk muscle and trunk neuromasts (red arrows) appear normal even in six1a;six1b double mutant embryos (I-L). Ear neuromasts (red arrows) are also normal in single and double mutants; however, ear cristae (bluearrows), a type of sensory epithelium, are small in six1b mutants and lost in six1a;six1b double mutants (M-P). Another ear sensory epithelium, the ventral macula (yellow arrows), is present even in double mutants. (Q-T) Ear cristae defects are also apparent in confocal sections of 120 hpf phalloidinlabeled embryos. All scale bars are 100 μm.