Fitness costs of disrupting circadian rhythms in malaria parasites
Aidan J. O'Donnell1,*, Petra Schneider2, Harriet G. McWatters3,† and Sarah E. Reece1,2,†
+Author Affiliations
1Institute of Evolution, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh EH9 3JT, UK
2Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3JT, UK
3Department of Plant Sciences, Oxford University, Oxford OX1 3RB, UK
* Author for correspondence (aidan.odonnell@ed.ac.uk).
↵† These authors contributed equally to the work.
Abstract
Circadian biology assumes that biological rhythms maximize fitness by enabling organisms to coordinate with their environment. Despite circadian clocks being such a widespread phenomenon, demonstrating the fitness benefits of temporal coordination is challenging and such studies are rare. Here, we tested the consequences—for parasites—of being temporally mismatched to host circadian rhythms using the rodent malaria parasite, Plasmodium chabaudi. The cyclical nature of malaria infections is well known, as the cell cycles across parasite species last a multiple of approximately 24 h, but the evolutionary explanations for periodicity are poorly understood. We demonstrate that perturbation of parasite rhythms results in a twofold cost to the production of replicating and transmission stages. Thus, synchronization with host rhythms influences in-host survival and between-host transmission potential, revealing a role for circadian rhythms in the evolution of host–parasite interactions. More generally, our results provide a demonstration of the adaptive value of circadian rhythms and the utility of using an evolutionary framework to understand parasite traits.
cell cycle, plasticity, periodicity, synchronicity, biological rhythms, Plasmodium chabaudi
Footnotes
Received November 10, 2010.
Accepted December 8, 2010.
This journal is © 2011 The Royal Society
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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