Fig. 1

polg2^ia304 line generation, survival and developmental delay.

A Schematic representation of zebrafish polg2 and its editing by CRISPR/Cas9. Bpolg2^ia304/ia304 individuals fail to survive to 4 weeks post fertilization. Data were analysed by χ2 test; p = 0.4165; p = 0.9802; p = 0.5617; p = 0.0438; p = 0.0226; p < 0.0001; 3 dpf (n = 120), 6 dpf (n = 115), 12 dpf (n = 89), 20 dpf (n = 70), 25 dpf (n = 50), 30 dpf (n = 46). Gene expression analysis performed to assess polg2 (C) and polg (D) mRNA levels in polg2^ia304 mutant line. Values are reported as mean ± SEM of three independent experiments and analysed by Games-Howell’s multiple comparison test (C) and ordinary one-way ANOVA followed by Tukey’s test (D); *p < 0.05; **p < 0.005; ***p < 0.001; polg2^+/+ (n = 6 × 10-larva pools), polg2^+/ia304 (n = 6 × 10-larva pools), polg2^ia304/ia304 (n = 4 × 10-larva pools). E Representative images of zebrafish polg2^+/+ control and polg2^ia304/ia304 mutant at 20 dpf, and polg2^+/+ control and a polg2^+/ia304 heterozygote at 90 dpf. Scale bar: 2 mm (top); scale bar: 1 cm (bottom). F Body length analysis in wt (polg2^+/+), heterozygous (polg2^+/ia304) and homozygous (polg2^ia304/ia304) individuals. Values are expressed as mean ± SEM. Statistics were assessed by Mann-Whitney test; ****p < 0.0001; polg2^+/+ 6 dpf (n = 25), polg2^+/ia304 6 dpf (n = 41), polg2^ia304/ia304 6 dpf (n = 22); polg2^+/+ 20 dpf (n = 39), polg2^+/ia304 20 dpf (n = 74), polg2^ia304/ia304 20 dpf (n = 45); polg2^+/+ 90 dpf (n = 8), polg2^+/ia304 90 dpf (n = 7).