Genomic editing using CRISPR/Cas9 to generate asxl1 C-terminally truncated mutant zebrafish.A Site-specific targeting for CRISPR/Cas9 cleavage within exon 12 of the zebrafish asxl1 gene. Alignment of nucleotide sequences from wild-type and mutant asxl1 alleles in asxl1e12 (−7) and asxl1e12 (−22) zebrafish lines. Dashes in DNA sequences are the nucleotides deleted during repair of CRISPR/Cas9-induced double-strand breaks. PAM protospacer adjacent motif. CRISPR/cas9-induced asxl1 frameshift mutations predicted to lead to C-terminally truncated proteins. Truncated proteins predicted from mutant alleles asxl1e12 (−7) and asxl1e12 (−22) lack the last two domains (ASXM2 and PHD). B qRT-PCR comparing expression of asxl1 in asxl1+/+ and mutant asxl1−/− in 3 days postfertilization (dpf) larvae and adult kidney marrow (3 dpf, 3 dpf larvae tails, n ≥ 10 per group, performed with four replicates; 6 m, 6-month kidney marrow, n = 4 per genotype; two-tailed Student’s t test, *p < 0.05, **p < 0.01, ***p < 0.001; error bars, mean ± standard deviation (SD)). C Gross appearance of asxl1−/− zebrafish compared with asxl1+/+ littermates (at 1.5 years). Body weights of asxl1+/+ and asxl1−/− zebrafish (scale bar, 1 cm; asxl1+/+, n = 33; asxl1−/−, n = 24; two-tailed Student’s t test, *p < 0.05, **p < 0.01, ***p < 0.001, error bars, mean ± SD).
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