title: A 'toxin mantle' as defensive barrier in a tropical bird: evolutionary exploitation of the basic permeability barrier forming organelles.
abstract: Birds in the genus Pitohui and Ifrita carry potent neurotoxins that are most abundant in skin and feathers. It was unknown precisely how or where in the skin these chemicals are stored. Here, we report high-resolution electron microscopy using OsO4 staining to visualize the location of alkaloids. Our images suggest that toxic alkaloids accumulate in multigranular bodies of epidermal cells and are likely secreted as part of the avian epidermal barrier, where they are made available for chemical defense.
authors.affiliation: Department of Ornithology and Mammalogy, California Academy of Sciences, San Francisco, CA, USA.
authors.forename: Gopinathan K
authors.initials: GK
authors.lastname: Menon
authors.forename: John P
authors.initials: JP
authors.lastname: Dumbacher
mesh_terms: D000470:Alkaloids / Q000378:metabolism*; D000818:Animals; D005075:Biological Evolution; D004817:Epidermis / Q000378:metabolism* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D009498:Neurotoxins / Q000378:metabolism*; D046109:Passeriformes / Q000502:physiology*
chemical_list: D000470:Alkaloids; D009498:Neurotoxins
keywords: lamellar bodies; skin barrier; toxin mantle