Molecular Info®

Molecular Info® Copy Right © 2001 Institute of Molecular Development LLC

Nitric Oxide and the Control of Firefly Flashing Barry A. Trimmer, June R. Aprille, David M. Dudzinski, Christopher J. Lagace, Sara M. Lewis, Thomas Michel, Sanjive Qazi, and Ricardo M. Zayas The Science, June 2001, 292: 2486-2488. Nitric oxide synthesis is a key determinant of flash control in fireflies. Firefly light production involves O2-dependent luciferin-luciferase reaction occuring within photocytes in abdomen. Inside each photocyte, mitochondria are clustered along the edge closest to the tracheal cells. When the light is off, these mitochondria are a barrier that soaks up oxygen before it reaches luciferin. When its time to flash, the nitric oxide concentration increases in the air-duct cells and diffuses over the mitochondria, briefly shutting down this oxygen barrier. In response, the oxygen concentration rises in the photocytes, setting off the light. The latern in and of itself turns off the nitric oxide reaction.