Figure 5. Autophagy is the prevalent programmed cell death pathway occurring in bleaching P. acuta. A) Analyses of caspase (top) and acid phosphatase (bottom) activity in corals under different treatments. The leftmost graphs show the respective enzymatic activities in preconditioned (PC) and non-preconditioned (NPC) corals under acute heat stress. While the activity of caspases doesn’t increase, the activity of acid phosphatases increases in all corals over time but is significantly higher in NPC corals when compared to PC (Anova, activity ~ conditioning+time+(1|Coral), p(conditioning) = 0.002, p(time) = 1.7e-06), n = 6. The middle graphs show the activity of respective enzymes in corals treated (ven+HT) and not treated (ven-HT) with venetoclax. While there is no apparent increase in caspase activity in corals, the activity of acid phosphatase varies between treatments. n = 4. The rightmost graphs show the activity of the respective enzymes in corals treated with rapamycin (rap, autophagy inducer) and colchicine (col, apoptosis inducer). As expected, the activity of caspases increases significantly upon colchicine treatment, while acid phosphatases are more active in rapamycin-treated corals. n = 4, bars represent standard errors. B) Expression of genes related to programmed cell death pathways, relative to control at time 0h. Control samples are depicted with the dotted line, NPC with the dashed line, and PC with the solid line. ΔΔCt method was used to calculate the relative expression. The variability of the measurements is visualized with boxplots where non-preconditioned corals are in white and preconditioned in grey. Dots represent outlining values. Random effect model with post-hoc Tukey independent for each gene/ratio was used to test the difference of the values. * marks significant (p ≦ 0.05), ‡ almost significant (p ≦ 0.1) difference between PC and NPC corals, n = 10.
Supplementary Figures
Figure S1