Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2008 Jul;77(4):768-76.
doi: 10.1111/j.1365-2656.2008.01399.x. Epub 2008 May 16.

Host Ecology Shapes Geographical Variation for Resistance to Bacterial Infection in Drosophila Melanogaster

Affiliations
Free PMC article

Host Ecology Shapes Geographical Variation for Resistance to Bacterial Infection in Drosophila Melanogaster

Vanessa Corby-Harris et al. J Anim Ecol. .
Free PMC article

Abstract

1. Geographically distinct host populations often experience very different ecological conditions. These variable ecological conditions impact the strength of selection that these hosts experience from their parasites. 2. Numerous studies have characterized geographical patterns of resistance to infection among natural populations in the context of host-parasite local adaptation, but what other factors might contribute to these differences? 3. Here, we determined whether 20 naturally isolated populations of Drosophila melanogaster collected along the East Coast of the United States varied for survival after being inoculated with one of two species of bacteria--Lactococcus lactis and Pseudomonas aeruginosa. We then asked whether host environment accounted for the observed patterns of resistance. 4. Resistance to both types of infection varied spatially. The hosts' natural environment was predictive of the observed spatial variation in resistance to L. lactis, but not P. aeruginosa, infection. Specifically, hosts exposed to species-rich bacterial communities were more likely to survive the infection. 5. We conclude that biotic characteristics of the host environment, specifically the number of species of bacteria hosts encounter, shape host resistance to bacterial infection in nature. We discuss our results in the context of what is known about the evolutionary ecology of resistance in invertebrate systems.

Figures

Fig. 1
Fig. 1
D. melanogaster were collected at twenty different locations along the East Coast of the United States. Numbers on the right side of the figure correspond to the population numbers in Fig. 2 and in Table 1. The grey box (left) indicates the range encompassed by the enlarged map on the right. Single points with two corresponding numbers represent separate locations ≤ 20 km apart. Map courtesy of http://www.lib.berkeley.edu
Fig. 2
Fig. 2
Populations of D. melanogaster varied for how well they resisted both P. aeruginosa (black) and L. lactis (grey) infection. Outbred host populations (x-axis) are arranged from left to right in order of decreasing latitude. Mortality post-inoculation (y-axis) represents each population's natural log transformed hazard ratio post-inoculation under a proportional hazards model. Values below the x-axis indicate resistance, while values above indicate susceptibility. Error bars represent the standard error around the transformed hazard ratio estimate. Host population was a significant predictor of time to death following inoculation for both the P. aeruginosa (Wald χ192=206.49, P < 0.0001) and L. lactis (Wald χ192=42.67, P = 0.0014) treatments.

Similar articles

See all similar articles

Cited by 14 articles

See all "Cited by" articles

Publication types

LinkOut - more resources

Feedback