title: Evidence for light perception in a bioluminescent organ.
abstract: Here we show that bioluminescent organs of the squid Euprymna scolopes possess the molecular, biochemical, and physiological capability for light detection. Transcriptome analyses revealed expression of genes encoding key visual transduction proteins in light-organ tissues, including the same isoform of opsin that occurs in the retina. Electroretinograms demonstrated that the organ responds physiologically to light, and immunocytochemistry experiments localized multiple proteins of visual transduction cascades to tissues housing light-producing bacterial symbionts. These data provide evidence that the light-organ tissues harboring the symbionts serve as extraocular photoreceptors, with the potential to perceive directly the bioluminescence produced by their bacterial partners.
authors.affiliation: Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA.
authors.forename: Deyan
authors.initials: D
authors.lastname: Tong
authors.forename: Natalia S
authors.initials: NS
authors.lastname: Rozas
authors.forename: Todd H
authors.initials: TH
authors.lastname: Oakley
authors.forename: Jane
authors.initials: J
authors.lastname: Mitchell
authors.forename: Nansi J
authors.initials: NJ
authors.lastname: Colley
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: McFall-Ngai
mesh_terms: D000818:Animals; D018407:Bacterial Physiological Phenomena; D049832:Decapodiformes / Q000502:physiology*; D004596:Electroretinography; D007150:Immunohistochemistry; D008027:Light; D049449:Luminescence; D008969:Molecular Sequence Data; D014796:Visual Perception