{"id":9387,"date":"2018-08-03T13:07:04","date_gmt":"2018-08-03T12:07:04","guid":{"rendered":"https:\/\/www.egce.universite-paris-saclay.fr\/?p=9387"},"modified":"2018-08-03T13:07:04","modified_gmt":"2018-08-03T12:07:04","slug":"etude-des-transferts-horizontaux-de-genes-de-guepes-parasitoides-a-leurs-lepidopteres-hotes","status":"publish","type":"post","link":"https:\/\/www.egce.universite-paris-saclay.fr\/?p=9387","title":{"rendered":"Etude des transferts horizontaux de g\u00e8nes de gu\u00eapes parasito\u00efdes \u00e0 leurs l\u00e9pidopt\u00e8res h\u00f4tes."},"content":{"rendered":"

Stage co-dirig\u00e9 par Cl\u00e9ment Gilbert (EGCE) et Elisabeth Huguet (IRBI, Tours)<\/p>\n

Email\u00a0: clement.gilbert@etce.cnrs-gif.fr<\/a><\/p>\n

La plupart des gu\u00eapes parasito\u00efdes (Hymenoptera, Ichneumonoidea) sont ko\u00efnobiontes, c\u2019est-\u00e0-dire qu\u2019elles effectuent leur d\u00e9veloppement larvaire \u00e0 l\u2019int\u00e9rieur des arthropodes qu\u2019elles parasitent en maintenant ceux-ci en vie jusqu\u2019\u00e0 leur propre nymphose (Beckage and Drezen 2012). Ce type d\u2019association intime et durable implique des interactions physiologiques et immunitaires relativement complexes entre les gu\u00eapes et leurs h\u00f4tes. Plusieurs familles de gu\u00eapes ont m\u00eame domestiqu\u00e9 des g\u00e8nes viraux int\u00e9gr\u00e9s dans leur g\u00e9nome, leur permettant de synth\u00e9tiser des particules virales non r\u00e9plicatives qu\u2019elles injectent en m\u00eame temps que leurs \u0153ufs dans les larves de leurs h\u00f4tes (Herniou et al. 2013 ; Drezen et al. 2017). Ces particules contiennent des facteurs de virulence (ADNs circulaires, prot\u00e9ines) qui att\u00e9nuent la r\u00e9ponse immunitaire de l\u2019h\u00f4te et facilitent ainsi le d\u00e9veloppement des larves de gu\u00eapes. Une \u00e9tude r\u00e9cente r\u00e9alis\u00e9e en laboratoire \u00e0 l\u2019Institut de Recherche sur la Biologie de l\u2019Insecte (IRBI ; universit\u00e9 de Tours) montre que de nombreuses copies des cercles d\u2019ADN encapsid\u00e9s dans les particules virales de la gu\u00eape Cotesia congregata<\/em> (Braconidae) sont int\u00e9gr\u00e9es de mani\u00e8re syst\u00e9matique, \u00e0 chaque infection, dans le g\u00e9nome des cellules immunitaires de son h\u00f4te (le sphinx du tabac, Manduca sexta<\/em>) (Chevignon et al. 2018). Ce ph\u00e9nom\u00e8ne de transformation g\u00e9nomique d\u2019un h\u00f4te par son parasite eucaryote est unique. Il pourrait permettre, en absence de r\u00e9plication virale, aux g\u00e8nes viraux d\u2019\u00eatre maintenus et exprim\u00e9s dans les cellules h\u00f4tes pendant tout le temps n\u00e9cessaire au d\u00e9veloppement des embryons de gu\u00eapes. Cependant, le r\u00f4le jou\u00e9 par ces int\u00e9grations et leur importance dans les interactions gu\u00eapes\/h\u00f4tes restent encore \u00e0 \u00e9claircir. Par ailleurs, on sait que certaines populations d\u2019h\u00f4tes peuvent devenir r\u00e9sistantes au parasitisme, et donc survivre aux infections. Si des int\u00e9grations de cercles d\u2019ADN de virus se produisaient dans la lign\u00e9e germinale de ces populations r\u00e9sistantes, elles pourraient \u00eatre transmises verticalement. Les interactions entre gu\u00eapes parasito\u00efdes et leurs h\u00f4tes offrent donc un contexte propice aux transferts horizontaux de mat\u00e9riel g\u00e9n\u00e9tique (TH) entre esp\u00e8ces.<\/p>\n

De mani\u00e8re g\u00e9n\u00e9rale, les TH semblent avoir jou\u00e9 un r\u00f4le plus important qu\u2019on ne le pensait auparavant dans l\u2019\u00e9volution des eucaryotes (Loreto et al. 2008; Schaack et al. 2010; Syvanen 2012; Boto 2014). Cependant les m\u00e9canismes expliquant ces transferts restent inconnus (Gilbert & Cordaux 2017). Plusieurs travaux montrent que des TH de g\u00e8nes de gu\u00eapes parasito\u00efdes \u00e0 des l\u00e9pidopt\u00e8res ont bien eu lieu dans le pass\u00e9 (Schneider and Thomas 2014; Gasmi et al. 2015). Mais ceux-ci sont trop anciens pour esp\u00e9rer comprendre comment ils se sont produits. La d\u00e9couverte des int\u00e9grations syst\u00e9matiques d\u2019ADN viraux associ\u00e9s aux gu\u00eapes dans les g\u00e9nomes de l\u00e9pidopt\u00e8res parasit\u00e9s offre une opportunit\u00e9 unique de faire la lumi\u00e8re sur un des m\u00e9canismes possibles de TH entre animaux.<\/p>\n

Le projet aura pour objectif de caract\u00e9riser la fr\u00e9quence des int\u00e9grations de cercles d’ADN d\u2019un virus d\u2019une gu\u00eape proche de C. congregata<\/em> (Cotesia typhae<\/em>, (Kaiser et al. 2017)) chez diff\u00e9rentes populations et esp\u00e8ces de l\u00e9pidopt\u00e8res. Il vise \u00e9galement \u00e0 \u00e9valuer la possibilit\u00e9 que ces int\u00e9grations se produisent dans la lign\u00e9e germinale et soient transmises verticalement chez des h\u00f4tes r\u00e9sistants. Les patrons d\u2019int\u00e9gration dans les cellules somatiques (h\u00e9mocytes, corps gras) et germinales seront compar\u00e9s entre populations sensibles et r\u00e9sistantes d\u2019une esp\u00e8ce de l\u00e9pidopt\u00e8re cible, la s\u00e9samie du ma\u00efs, Sesamia nonagrioides<\/em> (Benoist et al. 2017) et entre S. nonagrioides<\/em> et une esp\u00e8ce qui n\u2019est pas un h\u00f4te naturel (la pyrale du ma\u00efs, Ostrinia nubilalis<\/em>). Les int\u00e9grations seront recherch\u00e9es non seulement chez des individus parasit\u00e9s au laboratoire mais \u00e9galement dans des populations naturelles.<\/p>\n

 <\/p>\n

R\u00e9f\u00e9rences <\/strong><\/p>\n

Beckage, N. E., and J.-M. Drezen (Eds.), 2012 Parasitoid viruses: symbionts and pathogens. Elsevier\/Academic Press, London\u202f; New York.<\/p>\n

Benoist, R., C. Chantre, C. Capdevielle-Dulac, M. Bodet, F. Mougel et al., 2017 Relationship between oviposition, virulence gene expression and parasitism success in Cotesia typhae nov. sp. parasitoid strains. Genetica 145: 469\u2013479.<\/p>\n

Boto, L., 2014 Horizontal gene transfer in the acquisition of novel traits by metazoans. Proc Biol Sci 281: 20132450.<\/p>\n

Burke, G. R., S. A. Thomas, J. H. Eum, and M. R. Strand, 2013 Mutualistic Polydnaviruses Share Essential Replication Gene Functions with Pathogenic Ancestors (D. S. Schneider, Ed.). PLoS Pathog. 9: e1003348.<\/p>\n

Chevignon G, Periquet G, Gyapay G, Vega-Czarny N, Musset K, Drezen JM, Huguet E. Cotesia congregata Bracovirus Circles Encoding PTP and Ankyrin Genes Integrate into the DNA of Parasitized Manduca sexta Hemocytes. J Virol. 2018 92(15).<\/p>\n

Drezen, J.-M., M. Leobold, A. B\u00e9zier, E. Huguet, A.-N. Volkoff et al., 2017 Endogenous viruses of parasitic wasps: variations on a common theme. Curr. Opin. Virol. 25: 41\u201348.<\/p>\n

Gasmi, L., H. Boulain, J. Gauthier, A. Hua-Van, K. Musset et al., 2015 Recurrent Domestication by Lepidoptera of Genes from Their Parasites Mediated by Bracoviruses. PLoS Genet. 11: e1005470.<\/p>\n

Gilbert, C., and R. Cordaux, 2017 Viruses as vectors of horizontal transfer of genetic material in eukaryotes. Curr. Opin. Virol. 25: 16\u201322.<\/p>\n

Herniou, E. A., E. Huguet, J. Theze, A. Bezier, G. Periquet et al., 2013 When parasitic wasps hijacked viruses: genomic and functional evolution of polydnaviruses. Philos Trans R Soc Lond B Biol Sci 368: 20130051.<\/p>\n

Kaiser, L., J. Fernandez-Triana, C. Capdevielle-Dulac, C. Chantre, M. Bodet et al., 2017 Systematics and biology of Cotesia typhae sp. n. (Hymenoptera, Braconidae, Microgastrinae), a potential biological control agent against the noctuid Mediterranean corn borer, Sesamia nonagrioides. ZooKeys 682: 105\u2013136.<\/p>\n

Loreto, E. L., C. M. Carareto, and P. Capy, 2008 Revisiting horizontal transfer of transposable elements in Drosophila. Hered. Edinb 100: 545\u201354.<\/p>\n

Schaack, S., C. Gilbert, and C. Feschotte, 2010 Promiscuous DNA: horizontal transfer of transposable elements and why it matters for eukaryotic evolution. Trends Ecol Evol 25: 537\u201346.<\/p>\n

Schneider, S. E., and J. H. Thomas, 2014 Accidental genetic engineers: horizontal sequence transfer from parasitoid wasps to their Lepidopteran hosts. PloS One 9: e109446.<\/p>\n

Syvanen, M., 2012 Evolutionary implications of horizontal gene transfer. Annu. Rev. Genet. 46: 341\u201358.<\/p>\n

\u00a0<\/strong><\/p>\n

Contexte, comp\u00e9tences recherch\u00e9es, et encadrement<\/strong><\/p>\n

Nous recherchons un\/e \u00e9tudiant\/e enthousiaste et motiv\u00e9\/e et ayant de bonnes connaissances en \u00e9volution g\u00e9nomique. Une des t\u00e2ches principales du stage de M2 consistera \u00e0 assembler et annoter le g\u00e9nome de Sesamia nonagrioides <\/em>(en combinant des donn\u00e9es illumina et PacBio). L\u2019\u00e9tudiant\/e devra donc \u00eatre \u00e0 l\u2019aise sur un terminal Unix et de pr\u00e9f\u00e9rence maitriser au moins un langage de programmation. Id\u00e9alement, l\u2019\u00e9tudiant\/e r\u00e9aliserait aussi quelques manips pilotes de biologie mol\u00e9culaire de paillasse consistant \u00e0 rechercher par PCR des inserts de Cotesia typhae<\/em> dans des populations de l\u00e9pidopt\u00e8res. Nous pr\u00e9voyons de continuer ce projet sur la dur\u00e9e d\u2019une th\u00e8se, dont le financement devra \u00eatre acquis par l\u2019\u00e9tudiant\/e qui pourra postuler \u00e0 l\u2019\u00e9cole doctorale SDSV de l\u2019universit\u00e9 Paris-Saclay. Le stage se d\u00e9roulera enti\u00e8rement au laboratoire EGCE \u00e0 Gif sur Yvette et sera encadr\u00e9 par Cl\u00e9ment Gilbert (EGCE) et Elisabeth Huguet (IRBI, Tours).<\/p>\n","protected":false},"excerpt":{"rendered":"

Stage co-dirig\u00e9 par Cl\u00e9ment Gilbert (EGCE) et Elisabeth Huguet (IRBI, Tours) Email\u00a0: clement.gilbert@etce.cnrs-gif.fr La plupart des gu\u00eapes parasito\u00efdes (Hymenoptera, Ichneumonoidea) sont ko\u00efnobiontes, c\u2019est-\u00e0-dire qu\u2019elles effectuent leur d\u00e9veloppement larvaire \u00e0 l\u2019int\u00e9rieur des arthropodes qu\u2019elles parasitent en maintenant ceux-ci en vie jusqu\u2019\u00e0 leur propre nymphose (Beckage and Drezen 2012). Ce type d\u2019association intime et durable implique des […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_themeisle_gutenberg_block_has_review":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4,30,28,17],"tags":[],"class_list":["post-9387","post","type-post","status-publish","format-standard","hentry","category-iggipop","category-master-ii","category-stages","category-offres-demplois"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.egce.universite-paris-saclay.fr\/index.php?rest_route=\/wp\/v2\/posts\/9387","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.egce.universite-paris-saclay.fr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.egce.universite-paris-saclay.fr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.egce.universite-paris-saclay.fr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.egce.universite-paris-saclay.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=9387"}],"version-history":[{"count":0,"href":"https:\/\/www.egce.universite-paris-saclay.fr\/index.php?rest_route=\/wp\/v2\/posts\/9387\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.egce.universite-paris-saclay.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9387"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.egce.universite-paris-saclay.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9387"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.egce.universite-paris-saclay.fr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9387"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}