title: Firefly light flashing: oxygen supply mechanism.
abstract: Firefly luminescence is an intriguing phenomenon with potential technological applications, whose biochemistry background was only recently established. The physics side of this phenomenon, however, was still unclear, specifically as far as the oxygen supply mechanism for light flashing is concerned. This uncertainty is due to the complex microscopic structure of the tracheal system: without fully knowing its geometry, one cannot reliably test the proposed mechanisms. We solved this problem using synchrotron phase contrast microtomography and transmission x-ray microscopy, finding that the oxygen consumption corresponding to mitochondria functions exceeds the maximum rate of oxygen diffusion from the tracheal system to the photocytes. Furthermore, the flashing mechanism uses a large portion of this maximum rate. Thus, the flashing control requires passivation of the mitochondria functions, e.g., by nitric oxide, and switching of the oxygen supply from them to photoluminescence.
authors.affiliation: Institute of Physics, Academia Sinica, Taipei 115, Taiwan and Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 300, Taiwan.
authors.forename: Yueh-Lin
authors.initials: YL
authors.lastname: Tsai
authors.affiliation: Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 300, Taiwan.
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Li
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu 300, Taiwan.
authors.forename: Tzay-Ming
authors.initials: TM
authors.lastname: Hong
authors.affiliation: Endemic Species Research Institute, Nantou 552, Taiwan.
authors.forename: Jen-Zon
authors.initials: JZ
authors.lastname: Ho
authors.affiliation: Department of Entomology, National Taiwan University, Taipei 106, Taiwan.
authors.forename: En-Cheng
authors.initials: EC
authors.lastname: Yang
authors.affiliation: Department of Entomology, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Wen-Yen
authors.initials: WY
authors.lastname: Wu
authors.affiliation: Faculté des Sciences de Base, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Margaritondo
authors.affiliation: Institute of Physics, Academia Sinica, Taipei 115, Taiwan.
authors.forename: Su-Ting
authors.initials: ST
authors.lastname: Hsu
authors.affiliation: Institute of Physics, Academia Sinica, Taipei 115, Taiwan.
authors.forename: Edwin B L
authors.initials: EB
authors.lastname: Ong
authors.affiliation: Institute of Physics, Academia Sinica, Taipei 115, Taiwan and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hwu
mesh_terms: D000818:Animals; D048888:Fireflies / Q000378:metabolism*; D049449:Luminescence; D008928:Mitochondria / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D009569:Nitric Oxide; D010100:Oxygen