Figure 9.

Schematic representation of the ROS response of the D-box element in zebrafish and cavefish. In zebrafish cells (left panel), elevated levels of ROS are induced by exposure to both visible and UV light. Then, ROS activate MAPKs including p38 and JNK rapidly by phosphorylation and in turn activate the PAR factors. PAR factors bind to D-box enhancer elements in the promoters of a set of clock and DNA repair genes and ultimately lead to induced gene transcription and clock entrainment. In cavefish cells (right panel), this signaling fails to activate transcription of the same genes via the D-box [95].