Fig. 4.

The effect of ontogeny and developmental hypoxia on mitochondrial enzymatic activity. Enzymatic activity was measured in homogenized cardiac tissue from alligator embryos exposed to 21% and 10% oxygen during development (black and white bars, respectively) and their juvenile counterparts (dark and light gray bars, respectively) raised in 21% oxygen. Citrate synthase (A), and Complex I, II, IV, and V of the electron transport chain (B–E) were assayed using spectrophotometry (details in methods). Data are means ± SE. ψSignificant difference between embryos and adults (2-way ANOVA). P < 0.05, n = 6 for all experimental groups.