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The Origin of Intraspecific Variation of Virulence in an Eukaryotic Immune Suppressive Parasite
Occurrence of intraspecific variation in parasite virulence, a prerequisite for coevolution of hosts and parasites, has largely been reported. However, surprisingly little is known of the molecular bases of this variation in eukaryotic parasites, with the exception of the antigenic variation used by...
Autores principales: | , , , , |
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Formato: | Texto |
Lenguaje: | English |
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Public Library of Science
2010
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2991256/ https://www.ncbi.nlm.nih.gov/pubmed/21124871 http://dx.doi.org/10.1371/journal.ppat.1001206 |
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author | Colinet, Dominique Schmitz, Antonin Cazes, Dominique Gatti, Jean-Luc Poirié, Marylène |
author_facet | Colinet, Dominique Schmitz, Antonin Cazes, Dominique Gatti, Jean-Luc Poirié, Marylène |
author_sort | Colinet, Dominique |
collection | PubMed |
description | Occurrence of intraspecific variation in parasite virulence, a prerequisite for coevolution of hosts and parasites, has largely been reported. However, surprisingly little is known of the molecular bases of this variation in eukaryotic parasites, with the exception of the antigenic variation used by immune-evading parasites of mammals. The present work aims to address this question in immune suppressive eukaryotic parasites. In Leptopilina boulardi, a parasitic wasp of Drosophila melanogaster, well-defined virulent and avirulent strains have been characterized. The success of virulent females is due to a major immune suppressive factor, LbGAP, a RacGAP protein present in the venom and injected into the host at oviposition. Here, we show that an homologous protein, named LbGAPy, is present in the venom of the avirulent strain. We then question whether the difference in virulence between strains originates from qualitative or quantitative differences in LbGAP and LbGAPy proteins. Results show that the recombinant LbGAPy protein has an in vitro GAP activity equivalent to that of recombinant LbGAP and similarly targets Drosophila Rac1 and Rac2 GTPases. In contrast, a much higher level of both mRNA and protein is found in venom-producing tissues of virulent parasitoids. The F1 offspring between virulent and avirulent strains show an intermediate level of LbGAP in their venom but a full success of parasitism. Interestingly, they express almost exclusively the virulent LbGAP allele in venom-producing tissues. Altogether, our results demonstrate that the major virulence factor in the wasp L. boulardi differs only quantitatively between virulent and avirulent strains, and suggest the existence of a threshold effect of this molecule on parasitoid virulence. We propose that regulation of gene expression might be a major mechanism at the origin of intraspecific variation of virulence in immune suppressive eukaryotic parasites. Understanding this variation would improve our knowledge of the mechanisms of transcriptional evolution currently under active investigation. |
format | Text |
id | pubmed-2991256 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2010 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-29912562010-12-01 The Origin of Intraspecific Variation of Virulence in an Eukaryotic Immune Suppressive Parasite Colinet, Dominique Schmitz, Antonin Cazes, Dominique Gatti, Jean-Luc Poirié, Marylène PLoS Pathog Research Article Occurrence of intraspecific variation in parasite virulence, a prerequisite for coevolution of hosts and parasites, has largely been reported. However, surprisingly little is known of the molecular bases of this variation in eukaryotic parasites, with the exception of the antigenic variation used by immune-evading parasites of mammals. The present work aims to address this question in immune suppressive eukaryotic parasites. In Leptopilina boulardi, a parasitic wasp of Drosophila melanogaster, well-defined virulent and avirulent strains have been characterized. The success of virulent females is due to a major immune suppressive factor, LbGAP, a RacGAP protein present in the venom and injected into the host at oviposition. Here, we show that an homologous protein, named LbGAPy, is present in the venom of the avirulent strain. We then question whether the difference in virulence between strains originates from qualitative or quantitative differences in LbGAP and LbGAPy proteins. Results show that the recombinant LbGAPy protein has an in vitro GAP activity equivalent to that of recombinant LbGAP and similarly targets Drosophila Rac1 and Rac2 GTPases. In contrast, a much higher level of both mRNA and protein is found in venom-producing tissues of virulent parasitoids. The F1 offspring between virulent and avirulent strains show an intermediate level of LbGAP in their venom but a full success of parasitism. Interestingly, they express almost exclusively the virulent LbGAP allele in venom-producing tissues. Altogether, our results demonstrate that the major virulence factor in the wasp L. boulardi differs only quantitatively between virulent and avirulent strains, and suggest the existence of a threshold effect of this molecule on parasitoid virulence. We propose that regulation of gene expression might be a major mechanism at the origin of intraspecific variation of virulence in immune suppressive eukaryotic parasites. Understanding this variation would improve our knowledge of the mechanisms of transcriptional evolution currently under active investigation. Public Library of Science 2010-11-24 /pmc/articles/PMC2991256/ /pubmed/21124871 http://dx.doi.org/10.1371/journal.ppat.1001206 Text en Colinet et al. http://creativecommons.org/licenses/by/4.0/ 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 author and source are properly credited. |
spellingShingle | Research Article Colinet, Dominique Schmitz, Antonin Cazes, Dominique Gatti, Jean-Luc Poirié, Marylène The Origin of Intraspecific Variation of Virulence in an Eukaryotic Immune Suppressive Parasite |
title | The Origin of Intraspecific Variation of Virulence in an Eukaryotic Immune Suppressive Parasite |
title_full | The Origin of Intraspecific Variation of Virulence in an Eukaryotic Immune Suppressive Parasite |
title_fullStr | The Origin of Intraspecific Variation of Virulence in an Eukaryotic Immune Suppressive Parasite |
title_full_unstemmed | The Origin of Intraspecific Variation of Virulence in an Eukaryotic Immune Suppressive Parasite |
title_short | The Origin of Intraspecific Variation of Virulence in an Eukaryotic Immune Suppressive Parasite |
title_sort | origin of intraspecific variation of virulence in an eukaryotic immune suppressive parasite |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2991256/ https://www.ncbi.nlm.nih.gov/pubmed/21124871 http://dx.doi.org/10.1371/journal.ppat.1001206 |
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