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Immune response varies with rate of dispersal in invasive cane toads (Rhinella marina).

Brown GP, Shine R - PLoS ONE (2014)

Bottom Line: Toads that moved further showed decreased bacteria-killing ability in their plasma and decreased phagocytic activity in their whole blood, but a heightened skin-swelling response to phytohemagglutinin.Thus, long-distance movement in cane toads is associated with a dampened response in some systems and enhanced response in another.The finding that high mobility is accompanied by modification of the immune system has important implications for animal invasions.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, University of Sydney, Sydney, New South Wales, Australia.

ABSTRACT
What level of immunocompetence should an animal maintain while undertaking long-distance dispersal? Immune function (surveillance and response) might be down-regulated during prolonged physical exertion due to energy depletion, and/or to avoid autoimmune reactions arising from damaged tissue. On the other hand, heightened immune vigilance might be favored if the organism encounters novel pathogens as it enters novel environments. We assessed the links between immune defense and long-distance movement in a population of invasive cane toads (Rhinella marina) in Australia. Toads were radio-tracked for seven days to measure their activity levels and were then captured and subjected to a suite of immune assays. Toads that moved further showed decreased bacteria-killing ability in their plasma and decreased phagocytic activity in their whole blood, but a heightened skin-swelling response to phytohemagglutinin. Baseline and post-stress corticosterone levels were unrelated to distance moved. Thus, long-distance movement in cane toads is associated with a dampened response in some systems and enhanced response in another. This pattern suggests that sustained activity is accompanied by trade-offs among immune components rather than an overall down or up-regulation. The finding that high mobility is accompanied by modification of the immune system has important implications for animal invasions.

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Related in: MedlinePlus

Cane toad blood cells.Giemsa-stained cane toad blood smear with representative selection of blood cell types. Letters to the upper left of cells denote: (B) basophil, (E) eosinophil, (L) lymphocyte, (N) neutrophil, (r) erythrocyte, and (t) thrombocyte. Scale bar in the lower right indicates 10 µm.
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pone-0099734-g002: Cane toad blood cells.Giemsa-stained cane toad blood smear with representative selection of blood cell types. Letters to the upper left of cells denote: (B) basophil, (E) eosinophil, (L) lymphocyte, (N) neutrophil, (r) erythrocyte, and (t) thrombocyte. Scale bar in the lower right indicates 10 µm.

Mentions: We used blood smears to make differential counts of white blood cells, and hemocytometry to determine the concentration of blood cells in circulation. Blood smears were air dried overnight then fixed in methanol and stained using modified Giemsa. They were fitted with a cover glass and examined at 1000X. Slides were scanned and the first 100 white blood cells encountered were identified as basophil, eosinophil, monocyte, neutrophil or lymphocyte (Fig. 2). For hemocytometry, 10 µL of whole blood was added to 990 µL of Natt Herrick solution. The vial was then refrigerated for 60 min, after which time the vial was vortexed and 10 µL of the stained whole blood dilution was used to charge the chamber of a hemocytometer. We then examined the chamber under 400X magnification to count red and white blood cells [44].


Immune response varies with rate of dispersal in invasive cane toads (Rhinella marina).

Brown GP, Shine R - PLoS ONE (2014)

Cane toad blood cells.Giemsa-stained cane toad blood smear with representative selection of blood cell types. Letters to the upper left of cells denote: (B) basophil, (E) eosinophil, (L) lymphocyte, (N) neutrophil, (r) erythrocyte, and (t) thrombocyte. Scale bar in the lower right indicates 10 µm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061023&req=5

pone-0099734-g002: Cane toad blood cells.Giemsa-stained cane toad blood smear with representative selection of blood cell types. Letters to the upper left of cells denote: (B) basophil, (E) eosinophil, (L) lymphocyte, (N) neutrophil, (r) erythrocyte, and (t) thrombocyte. Scale bar in the lower right indicates 10 µm.
Mentions: We used blood smears to make differential counts of white blood cells, and hemocytometry to determine the concentration of blood cells in circulation. Blood smears were air dried overnight then fixed in methanol and stained using modified Giemsa. They were fitted with a cover glass and examined at 1000X. Slides were scanned and the first 100 white blood cells encountered were identified as basophil, eosinophil, monocyte, neutrophil or lymphocyte (Fig. 2). For hemocytometry, 10 µL of whole blood was added to 990 µL of Natt Herrick solution. The vial was then refrigerated for 60 min, after which time the vial was vortexed and 10 µL of the stained whole blood dilution was used to charge the chamber of a hemocytometer. We then examined the chamber under 400X magnification to count red and white blood cells [44].

Bottom Line: Toads that moved further showed decreased bacteria-killing ability in their plasma and decreased phagocytic activity in their whole blood, but a heightened skin-swelling response to phytohemagglutinin.Thus, long-distance movement in cane toads is associated with a dampened response in some systems and enhanced response in another.The finding that high mobility is accompanied by modification of the immune system has important implications for animal invasions.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, University of Sydney, Sydney, New South Wales, Australia.

ABSTRACT
What level of immunocompetence should an animal maintain while undertaking long-distance dispersal? Immune function (surveillance and response) might be down-regulated during prolonged physical exertion due to energy depletion, and/or to avoid autoimmune reactions arising from damaged tissue. On the other hand, heightened immune vigilance might be favored if the organism encounters novel pathogens as it enters novel environments. We assessed the links between immune defense and long-distance movement in a population of invasive cane toads (Rhinella marina) in Australia. Toads were radio-tracked for seven days to measure their activity levels and were then captured and subjected to a suite of immune assays. Toads that moved further showed decreased bacteria-killing ability in their plasma and decreased phagocytic activity in their whole blood, but a heightened skin-swelling response to phytohemagglutinin. Baseline and post-stress corticosterone levels were unrelated to distance moved. Thus, long-distance movement in cane toads is associated with a dampened response in some systems and enhanced response in another. This pattern suggests that sustained activity is accompanied by trade-offs among immune components rather than an overall down or up-regulation. The finding that high mobility is accompanied by modification of the immune system has important implications for animal invasions.

Show MeSH
Related in: MedlinePlus