Do Coinfections Maintain Genetic Variation in Parasites?
Host individuals are often infected with multiple, potentially interacting parasite species and genotypes. Such coinfections have consequences for epidemiology, disease severity, and evolution of parasite virulence. As fitness effects of coinfection can be specific to interacting parasite genotypes, coinfections may induce high fitness variation among parasite genotypes. We argue that such interactions can be an important mechanism maintaining genetic variation in parasite traits such as infectivity and virulence. We also argue that such interactions may slow coevolutionary dynamics between hosts and parasites. This is because, instead of depending only on host genotype, parasite fitness may be determined by average infection success across all coinfection scenarios.
Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; ETH Zürich, Institute of Integrative Biology (IBZ), 8092 Zürich, Switzerland. Electronic address: otto.seppaelae@eawag.ch.
Otto
O
Seppälä
Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; ETH Zürich, Institute of Integrative Biology (IBZ), 8092 Zürich, Switzerland.
Jukka
J
Jokela
D000818:Animals; D060085:Coinfection / Q000469:parasitology*; D014644:Genetic Variation; D005838:Genotype; D006790:Host-Parasite Interactions; D010271:Parasites / Q000235:genetics* / Q000472:pathogenicity