Fig. S1

Mutation reporters show that an artificial hace1 4-bp deletion in the middle of hace1 cDNA fragment induces efficient frameshifting. A: Representative images of 16-18 hpf (ca 16-somite) stage zebrafish embryos injected with the wild-type hace1 mutation reporter or a reporter construct with a 4-bp deletion mutation after the first 106 codons. Fluorescence images of superfolder GFP (sfGFP), TagRFP and a merged image are shown. B: Areas in the somite regions of these embryos were quantified by measuring fluorescence intensities of both sfGFP and TagRFP, adjusted for background in the corresponding channel and the ratio of these intensities was calculated to account for injection variability and used for plotting the data and statistical analysis. The difference between wild-type (n = 17) and 4-bp deletion mutant (n = 18) mutation reporters was large and very significant (Student’s twotailed t-test: p-value = 3.27e-14). The fact of p-value being less than 0.001 is marked with “***”. The embryos from two independent injections were subjected to imaging and statistical analysis of fluorescent protein intensities ratios.