Figure 4

Death rate of the lev-11 ( x12 ), daf-2 (hypoxia-resistant) and daf-16 (hypoxia-sensitive) mutants and that of the wild type animals (N2) exposed to 8, 10, 12, 14 and 16 h of hypoxia (0.2% oxygen) and after a 24-h recovery (21% oxygen). The death rate of the wild type N2 strain and lev-11(x12) mutant gradually increased as the time under hypoxic conditions increased. The daf-2 mutants were highly resistant to hypoxia, whereas the daf-16 mutants were highly sensitive to hypoxia. The death rate was significantly different when the wild type animals (8.85% ± 3.50, 26.44% ± 7.96) were compared with the lev-11 (x12) strain (27.64% ± 6.30, 64.06% ± 12.00) after 12 h and 14 h of hypoxia treatment, respectively (P = 0.0183, P = 0.0401). After 12 h of hypoxia, the death rate of the lev-11 (x12) strain was higher than that of the daf-16 mutant. The results are displayed as means ± standard deviation, n > 3, *: P < 0.05.