Holly Sewell 23 July 2010 Marine Biolumin escence

Experiment Organisms and Environments Where is it found? Function Proposed explanations Genes Reaction

Experiment : Can we isolate bioluminescent colonies? SWC

Bacterial Bioluminescence Where is it found? Photobacterium Vibrio Photorhabdus Some colonize light organs, producing light for animal for signaling avoiding predators attracting prey Parasites in crustacea Estimated 1-6x10 3 free-living bioluminescent bacteria per liter of water

Proposed explanation for bacterial bioluminescence Anaerobic bacteria may have developed bioluminescence to use up toxic oxygen (Tett & Kelley, 1973) Catalyze the transfer of electrons to oxygen (Nealson & Hastings, 1979) High population density quorum sensing: attract animals to feed  dispersal of population (Microbiology, Brock) Stimulation of DNA repair (Czyz et. al, 2000)

Bioluminescence Genes lux I AI lux R AI Activation of luminescence genes

Bioluminescence reaction: How it works Luciferin + O 2 Oxyluciferin + Light Luciferase ATP AMP + PPi RCOOH RCHO Oxidoreductase NAD(P)H + H + NAD(P) + NAD(P)H + H + NAD(P) + Fatty Acid Reductase Luciferase O2O2 Light FMNH 2 + O 2 + RCHO FMN + RCOOH + H 2 O + Light Luciferase

Question s?

An Example of Bacterial Bioluminescence Light Organ colonization in Euprymna scolopes Colonized by Vibrio fischeri both light and presence important for development of squid