Figure 5.

Tentative mechanisms of mitochondrial reactive oxygen species (ROS) production in ART by mode and site. Mode 1 (see Table 2) is likely to operate in at least some mitochondria, and is likely driven by complex I forward electron transfer. It is possible that complex II also operates in mode 1. Inhibitor studies (see main text) reveal forward mode is unlikely to operate in mode 2, since rotenone fails to increase ROS production in zygotes. The relative importance of mode 3 and 4 will depend on Δp and the redox state of the Q pool. Inhibitor studies (see main text) support a role for RET.