Fig. 2

Egr1 was substantially knocked down by antisense morpholino up to 120 hpf.

Compared with the uninjected embryos (uninjected; A) and controls (5misCTLMO; B) which had no obvious change in gross morphology, 89.3% (134/150) of the Egr1 morphants (egr1sMO; C) displayed a reduced eye size and a shortened body trunk at 72 hpf. This problem persisted to 120 hpf, at which the Egr1 morphants (F) were still noticeably shorter than the controls (D & E). Scale bar = 200 µm. The amount of the mature egr1 mRNA in the samples was measured by qPCR in order to determine the efficiency of the splice-blocking effect. The ratio and ratio range of the mRNA between Egr1 morphants and controls at 48, 72, 96 and 120 hpf were plotted in (G). The calculation of ratio and ratio range was conducted with the standard ΔΔCt method [47] as described in Methods. Overall, only about 20–40% of mature mRNA was detected in the Egr1 morphants until 5 dpf. (H) A boxplot of the eye-to-body ratios of the controls and Egr1 morphants. The anterior-posterior length of the eyes, when normalized by the body length, revealed a specific reduction of the eye size in the Egr1 morphants at both 72 and 120 hpf. Asterisks: p<0.05.