Heritable variation in host tolerance and resistance inferred from a wild host-parasite system.
Hosts have evolved two distinct defence strategies against parasites: resistance (which prevents infection or limit parasite growth) and tolerance (which alleviates the fitness consequences of infection). However, heritable variation in resistance and tolerance and the genetic correlation between these two traits have rarely been characterized in wild host populations. Here, we estimate these parameters for both traits in Leuciscus burdigalensis, a freshwater fish parasitized by Tracheliastes polycolpus. We used a genetic database to construct a full-sib pedigree in a wild L. burdigalensis population. We then used univariate animal models to estimate inclusive heritability (i.e. all forms of genetic and non-genetic inheritance) in resistance and tolerance. Finally, we assessed the genetic correlation between these two traits using a bivariate animal model. We found significant heritability for resistance (H = 17.6%; 95% CI: 7.2-32.2%) and tolerance (H = 18.8%; 95% CI: 4.4-36.1%), whereas we found no evidence for the existence of a genetic correlation between these traits. Furthermore, we confirm that resistance and tolerance are strongly affected by environmental effects. Our results demonstrate that (i) heritable variation exists for parasite resistance and tolerance in wild host populations, and (ii) these traits can evolve independently in populations.
Centre National de la Recherche Scientifique (CNRS), Station d'Ecologie Expérimentale du CNRS à Moulis, , USR 2936, 09200 Moulis, France, Université de Toulouse, , UPS, UMR5174 EDB (Laboratoire Évolution and Diversité Biologique), 118 route de Narbonne, 31062 Toulouse Cedex, France, Department of Ecology and Evolution, University of Chicago, , 1101 E 57th Street, Erman 103, Chicago, IL 60637, USA, Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC) UMR (IRD/CNRS/UM) 5290, , Centre IRD-911 Avenue Agropolis, BP 64501 Montpellier, France, Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier, École Nationale de Formation Agronomique (ENFA), UMR5174 EDB (Laboratoire Évolution and Diversité Biologique), , 118 route de Narbonne, 31062 Toulouse Cedex 4, France.
Elise
E
Mazé-Guilmo
Géraldine
G
Loot
David J
DJ
Páez
Thierry
T
Lefèvre
Simon
S
Blanchet
D000818:Animals; D003530:Cyprinidae / Q000469:parasitology*; D060467:Disease Resistance / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D006790:Host-Parasite Interactions / Q000235:genetics*
genetic correlation; host–parasite interaction; long-term survey; molecular-based pedigree; quantitative genetics