Protein-poor diet reduces host-specific immune gene expression in Bombus terrestris.
Parasites infect hosts non-randomly as genotypes of hosts vary in susceptibility to the same genotypes of parasites, but this specificity may be modulated by environmental factors such as nutrition. Nutrition plays an important role for any physiological investment. As immune responses are costly, resource limitation should negatively affect immunity through trade-offs with other physiological requirements. Consequently, nutritional limitation should diminish immune capacity in general, but does it also dampen differences among hosts? We investigated the effect of short-term pollen deprivation on the immune responses of our model host Bombus terrestris when infected with the highly prevalent natural parasite Crithidia bombi. Bumblebees deprived of pollen, their protein source, show reduced immune responses to infection. They failed to upregulate a number of genes, including antimicrobial peptides, in response to infection. In particular, they also showed less specific immune expression patterns across individuals and colonies. These findings provide evidence for how immune responses on the individual-level vary with important elements of the environment and illustrate how nutrition can functionally alter not only general resistance, but also alter the pattern of specific host-parasite interactions.
School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK Experimental Ecology, Institute of Integrative Biology, ETH Zürich, Universitätsstrasse 16, 8092 Zürich, Switzerland.
Franziska S
FS
Brunner
Experimental Ecology, Institute of Integrative Biology, ETH Zürich, Universitätsstrasse 16, 8092 Zürich, Switzerland.
Paul
P
Schmid-Hempel
Experimental Ecology, Institute of Integrative Biology, ETH Zürich, Universitätsstrasse 16, 8092 Zürich, Switzerland seth@env.ethz.ch.
Seth M
SM
Barribeau
D000818:Animals; D001516:Bees / Q000201:enzymology / Q000235:genetics* / Q000276:immunology / Q000469:parasitology; D003421:Crithidia / Q000502:physiology; D004032:Diet; D004044:Dietary Proteins / Q000378:metabolism; D005508:Food Deprivation / Q000502:physiology; D005786:Gene Expression Regulation; D007113:Immunity, Innate / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D014442:Monophenol Monooxygenase / Q000097:blood; D011058:Pollen / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
D004044:Dietary Proteins; D019476:Insect Proteins; D014442:Monophenol Monooxygenase
Bombus terrestris; Crithidia bombi; ecological immunology; gene expression; host–parasite interactions; nutrition