Printer Friendly

Avian Dis.: Enhanced innate immune responses in a brood parasitic cowbird species: degranulation and oxidative burst.

We examined the relative effectiveness of 2 innate immune responses in 2 species of New World blackbirds (Passeriformes, Icteridae) that differ in resistance to West Nile virus (WNV). We measured degranulation and oxidative burst, 2 fundamental components of phagocytosis, and we predicted that the functional effectiveness of these innate immune responses would correspond to the species' relative resistance to WNV. The brown-headed cowbird (Molothrus ater), an obligate brood parasite, had previously shown greater resistance to infection with WNV, lower viremia and faster recovery when infected, and lower subsequent antibody titers than the red-winged blackbird (Agelaius phoeniceus), a close relative that is not a brood parasite. We found that cowbird leukocytes were significantly more functionally efficient than those of the blackbird leukocytes and 50% more effective at killing the challenge bacteria. These results suggest that further examination of innate immunity in the cowbird may provide insight into adaptations that underlie its greater resistance to WNV. These results support an eco-immunological interpretation that species such as the cowbird, which inhabit ecological niches with heightened exposure to parasites, experience evolutionary selection for more-effective immune responses.


COPYRIGHT 2013 Association of Avian Veterinarians
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2013 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Hahn, D.C.; Summers, S.G.; Genovese, K.J.
Publication:Journal of Avian Medicine and Surgery
Article Type:Brief article
Date:Sep 1, 2013
Previous Article:Avian Dis.: Evaluation of Maryland backyard flocks and biosecurity practices.
Next Article:J Zoo Wildl Med.: Comparison of intranasal administration of xylazine, diazepam, and midazolam in budgerigars (Meiopsittacus undulates): clinical...

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters