Figure 5

Stc2a regulates the growth-survival trade-off under hypoxia. (A, B) Loss of Stc2a attenuates hypoxia-induced growth retardation and developmental delay. Fish of the indicated genotypes were subjected to hypoxia (filled bar) or normoxia (open bar) from 25–51 hpf. Body length (A) and head-trunk angle (HTA) (B) were measured and shown as mean ± SEM. n = 10~20. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, t-test. (C, D) Fish of the indicated genotypes were subjected to hypoxia treatment from 25–51 hpf in the presence or absence of 8 μM ZnCl₂. Body length (C) and HTA (D) was measured and shown as mean ± SEM. n = 58~73. ***p < 0.001, ****p < 0.0001, One-way ANOVA with multiple comparisons. (E) Fish (5 dpf) of the indicated genotypes were exposed to hypoxia (3% O₂) and survival rates were assessed and shown. ****p < 0.0001, Mantel-Cox log rank test. n = 42-100. (F) Fish (5 dpf) of the indicated genotypes were exposed to hypoxia (3% O₂) in the presence or absence of 8 μM ZnCl₂. The number of survival fish were assessed at the indicated time. **p < 0.01, ns, not significant. Mantel-Cox log rank test, n = 45-90.