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Colorful songbirds metabolize carotenoids at the integument
- Source :
- Journal of Avian Biology. 35:471-476
- Publication Year :
- 2004
- Publisher :
- Wiley, 2004.
-
Abstract
- For decades, carotenoids have attracted attention for their roles as vitamin-A precursors, antioxidants, and immunostimulants, but we still understand very little about the metabolic processes that accompany these compounds. Animals like birds use carotenoids to color their feathers and bare parts to become sexually attractive. They commonly metabolically derive their body colorants from dietary sources of carotenoids, but the sites of pigment metabolism remain unidentified. Here I test the hypothesis that songbirds manufacture their colorful feather and beak carotenoids directly at these tissues. I offer two lines of evidence to support this idea: (1) in a study of 11 colorful species from three passerine families, metabolically derived feather and beak carotenoids were found neither in the liver (a purported site of carotenoid metabolism), nor in the bloodstream (the means by which metabolites would be transported to colorful tissues from anywhere else in the body) at the time when pigments were being deposited into keratinized tissue, and (2) in a more detailed study of pigmentation in the American goldfinch Carduelis tristis, carotenoids sampled from the lipid fractions of maturing feather follicles yielded a mix of dietary and synthetic carotenoids, suggesting that this is the metabolically active site for feather-pigment production. This fresh perspective on carotenoid metabolism in animals should aid our efforts to characterize the responsible enzymes and to better understand the localized biological functions of these pigments.
- Subjects :
- chemistry.chemical_classification
animal structures
biology
organic chemicals
Lipid fraction
food and beverages
Zoology
macromolecular substances
Carotenoid metabolism
Passerine
The integument
Pigment
Beak
chemistry
biology.animal
visual_art
Feather
Botany
visual_art.visual_art_medium
Animal Science and Zoology
Carotenoid
Ecology, Evolution, Behavior and Systematics
Subjects
Details
- ISSN :
- 1600048X and 09088857
- Volume :
- 35
- Database :
- OpenAIRE
- Journal :
- Journal of Avian Biology
- Accession number :
- edsair.doi...........87945f9455d78329a974bbe91d0f3d65