Nematode endoparasites do not codiversify with their stick insect hosts.

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Ressource 1Télécharger: BIB_938B08C65601.P001.pdf (1607.28 [Ko])
Etat: Serval
Version: Final published version
ID Serval
serval:BIB_938B08C65601
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Nematode endoparasites do not codiversify with their stick insect hosts.
Périodique
Ecology and Evolution
Auteur(s)
Larose C., Schwander T.
ISSN
2045-7758 (Electronic)
ISSN-L
2045-7758
Statut éditorial
Publié
Date de publication
2016
Peer-reviewed
Oui
Volume
6
Numéro
15
Pages
5446-5458
Langue
anglais
Résumé
Host-parasite coevolution stems from reciprocal selection on host resistance and parasite infectivity, and can generate some of the strongest selective pressures known in nature. It is widely seen as a major driver of diversification, the most extreme case being parallel speciation in hosts and their associated parasites. Here, we report on endoparasitic nematodes, most likely members of the mermithid family, infecting different Timema stick insect species throughout California. The nematodes develop in the hemolymph of their insect host and kill it upon emergence, completely impeding host reproduction. Given the direct exposure of the endoparasites to the host's immune system in the hemolymph, and the consequences of infection on host fitness, we predicted that divergence among hosts may drive parallel divergence in the endoparasites. Our phylogenetic analyses suggested the presence of two differentiated endoparasite lineages. However, independently of whether the two lineages were considered separately or jointly, we found a complete lack of codivergence between the endoparasitic nematodes and their hosts in spite of extensive genetic variation among hosts and among parasites. Instead, there was strong isolation by distance among the endoparasitic nematodes, indicating that geography plays a more important role than host-related adaptations in driving parasite diversification in this system. The accumulating evidence for lack of codiversification between parasites and their hosts at macroevolutionary scales contrasts with the overwhelming evidence for coevolution within populations, and calls for studies linking micro- versus macroevolutionary dynamics in host-parasite interactions.
Mots-clé
Codiversification, cophylogeny, endoparasite, host-parasite interaction
Pubmed
Web of science
Open Access
Oui
Création de la notice
03/06/2016 10:57
Dernière modification de la notice
08/05/2019 22:10
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