Defenses against keratinolytic bacteria in birds living in radioactively contaminated areas
Autor: | Anders Pape Møller, Juan José Soler, Magdalena Ruiz-Rodríguez, Timothy A. Mousseau |
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Přispěvatelé: | Junta de Andalucía, Ministerio de Economía y Competitividad (España) |
Rok vydání: | 2016 |
Předmět: |
0106 biological sciences
Male Bodily Secretions animal structures Microorganism Denmark Adaptation Biological Zoology Hirundo rustica Antimicrobial defense 010603 evolutionary biology 01 natural sciences 010605 ornithology Chernobyl Uropygium Exocrine Glands Sex Factors Hirundo Animals Bacillus licheniformis Feather-degrading bacteria Selection Genetic Ecology Evolution Behavior and Systematics biology Ecology General Medicine Environmental exposure Environmental Exposure Contamination Feathers biology.organism_classification Chernobyl Nuclear Accident Swallows Feather visual_art visual_art.visual_art_medium Keratins Female Ukraine Barn (unit) Bacteria |
Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
ISSN: | 1432-1904 2013-4819 |
Popis: | Microorganisms have shaped the evolution of a variety of defense mechanisms against pathogenic infections. Radioactivity modifies bacterial communities and, therefore, bird hosts breeding in contaminated areas are expected to adapt to the new bacterial environment. We tested this hypothesis in populations of barn swallows (Hirundo rustica) from a gradient of background radiation levels at Chernobyl and uncontaminated controls from Denmark. Investment in defenses against keratinolytic bacteria was measured from feather structure (i.e., susceptibility to degradation) and uropygial secretions. We studied degradability of tail feathers from areas varying in contamination in laboratory experiments using incubation of feathers with a feather-degrading bacterium, Bacillus licheniformis, followed by measurement of the amount of keratin digested. The size of uropygial glands and secretion amounts were quantified, followed by antimicrobial tests against B. licheniformis and quantification of wear of feathers. Feathers of males, but not of females, from highly contaminated areas degraded at a lower rate than those from medium and low contamination areas. However, feathers of both sexes from the Danish populations showed little evidence of degradation. Individual barn swallows from the more contaminated areas of Ukraine produced the largest uropygial secretions with higher antimicrobial activity, although wear of feathers did not differ among males from different populations. In Denmark, swallows produced smaller quantities of uropygial secretion with lower antimicrobial activity, which was similar to swallow populations from uncontaminated areas in Ukraine. Therefore, barn swallows breeding in contaminated areas invested more in all defenses against keratinolytic bacteria than in uncontaminated areas of Ukraine and Denmark, although they had similar levels of feather wear. Strong natural selection exerted by radioactivity may have selected for individuals with higher defense capacity against bacterial infections during the 30 years since the Chernobyl disaster. M. Ruiz-Rodríguez had a Postdoc from the program “Andalucía Talent Hub” (Agencia Andaluza del Conocimiento, Junta de Andalucía). Funding was provided in part from the Samuel Freeman Charitable Trust, the US Fulbright Program, the CNRS (France), the American Council of Learned Societies, the University of South Carolina College of Arts and Sciences, and the Spanish Ministerio de Economía y Competitividad (European funds (FEDER)) (CGL2013-48193-C3-1-P). |
Databáze: | OpenAIRE |
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