23 research outputs found
MATASELLOS HISPANIDAD [Material grĂĄfico]
Copia digital. Madrid : Ministerio de EducaciĂłn, Cultura y Deporte, 201
Study about the production mechanism of the DNA encapsidated in bracovirus particle in the parasitoid wasp Cotesia congregata
Les bracovirus forment une symbiose avec les guĂȘpes parasitoĂŻdes, demeurant dans leur gĂ©nome et produits uniquement dans leurs ovaires. Nous avons caractĂ©risĂ© comment les cercles dâADNdb contenu dans les particules Ă©taient amplifiĂ©s depuis leur forme provirale avant leur encapsidation.Nous avons montrĂ© que le site dâintĂ©gration du gĂ©nome viral est conservĂ© chez les bracovirus et organisĂ© dans le gĂ©nome de la guĂȘpe en un macrolocus regroupant la majoritĂ© des segments proviraux et 7 loci isolĂ©s. Nous avons mis en Ă©vidence 12 unitĂ©s de rĂ©plication (UR) et que les 9 gĂšnes viraux du cluster nudiviral Ă©taient amplifiĂ©s sur une UR sans ĂȘtre encapsidĂ©s. Nous avons identifiĂ© des concatĂ©mĂšres tĂȘte-tĂȘte et queue-queue comme Ă©tant les intermĂ©diaires de rĂ©plication des UR, caractĂ©ristiques dâune rĂ©plication linĂ©aire du gĂ©nome viral. Enfin, nous avons montrĂ© que lâADN polymĂ©rase B2 appartenait Ă un Ă©lĂ©ment Maverick. Lâabsence de gĂšnes viraux de la rĂ©plication du gĂ©nome viral semble indiquer que la machinerie rĂ©plicative cellulaire serait impliquĂ©e. Il reste maintenant Ă mettre en Ă©vidence les diffĂ©rents facteurs cellulaires participant Ă lâamplification du gĂ©nome viral.Bracovirus form a symbiosis with parasitoid wasp, remaining in their genome and products only in their ovaries. We characterized how packaged dsDNA circles were amplified from their proviral genome before packaging in viral particles.We showed that viral genome integration site is conserved in bracovirus and organized in the wasp genome in a macrolocus where the majority of proviral segments was found and 7 isolated loci. We showed 12 replication units (UR) and the 9 nudiviral genes from cluster were amplified on a UR without being packaged. We identified concatemers head-head and tail-tail as the replication intermediates of UR, indicating a linear replication of the viral genome. Finally, we showed that DNA polymerase B2 belonged to a Maverick element.The absence of viral gene involved in the genome replication suggests that the cellular replication machinery is involved. It remains to highlight the different cellular factors involved in the amplification of the viral genome
Origin and evolution of symbiotic viruses associated with parasitoid wasps
National audienceThe Polydnaviridae (PDV), including the Bracovirus (BV) and Ichnovirus (IV) genera, originated from the integration of viruses in the genomes of two parasitoid wasp lineages. In a remarkable example of convergent evolution BVs evolved from the domestication of a nudivirus, while IVs originate from a different ancestral virus belonging to a new virus entity. In both cases the ancestor genomes have been maintained in wasp genomes as endogenous viral elements involved in production of particles containing DNA encoding virulence genes that are injected into lepidopteran hosts. However many PDV virulence genes appear to be of eukaryotic origin, and expansion and diversification of these genes have led to the production of novel PDVs in different wasp species that promote survival of offspring in particular hosts
CAXII Is a Surrogate Marker for Luminal Breast Tumors Regulated by ER and GATA3
Estrogen receptor alpha (ERα) expression in ~2/3 breast tumors selects patients for hormonal therapies. Tumors negative for ERα but positive for the progesterone receptor (PR, encoded by PGR) have also been candidates for ER-targeting therapies, as PR expression may reflect undetected ER activity. Conversely, PRâ status in ER+ tumors predicts a worse therapeutic response. Our analysis of breast tumor transcriptome datasets, however, revealed that in tumors with lower PGR expression, the clinical PR status does not correlate accurately with the expression of ESR1 or of ER target genes, including PGR itself. We identified carbonic anhydrase 12 (CA12) as an estrogen target gene better correlated with ESR1 than PGR, reflecting CA12 regulation by both ERα and the luminal factor and upstream ESR1 regulator GATA3. Immunostaining supported strong positive correlations at the protein level with ERα and GATA3 in a cohort of 118 tumors. Most ER+PRâ tumors expressed CAXII at levels similar to those of ER+PR+ tumors, consistent with observations in tumor transcriptome datasets and with active estrogenic signaling in some ER+PRâ breast cancer cell lines. The few ERâPR+ tumors did not express CAXII or the other luminal markers FOXA1 and GATA3. Overall, CAXII is a luminal marker that can help interpret ER status in single ER/PR positive tumors
Transfer of a chromosomal Maverick to endogenous bracovirus in a parasitoid wasp
International audienceBracoviruses are used by parasitoid wasps to allow development of their progeny within the body of lepidopteran hosts. In parasitoid wasps, the bracovirus exists as a provirus, integrated in a wasp chromosome. Viral replication occurs in wasp ovaries and leads to formation of particles containing dsDNA circles (segments) that are injected into the host body during wasp oviposition. We identified a large DNA transposon Maverick in a parasitoid wasp bracovirus. Closely related elements are present in parasitoid wasp genomes indicating that the element in CcBV corresponds to the insertion of an endogenous wasp Maverick in CcBV provirus. The presence of the Maverick in a bracovirus genome suggests the possibility of transposon transfers from parasitoids to lepidoptera via bracoviruses
The Bracovirus Genome of the Parasitoid Wasp Cotesia congregata Is Amplified within 13 Replication Units, Including Sequences Not Packaged in the Particles
International audienceThe relationship between parasitoid wasps and polydnaviruses constitutes one of the few known mutualisms between viruses and eukaryotes. Viral particles are injected with the wasp eggs into parasitized larvae, and the viral genes thus introduced are used to manipulate lepidopteran host physiology. The genome packaged in the particles is composed of 35 double-stranded DNA (dsDNA) circles produced in wasp ovaries by amplification of viral sequences from proviral segments integrated in tandem arrays in the wasp genome. These segments and their flanking regions within the genome of the wasp Cotesia congregata were recently isolated, allowing extensive mapping of amplified sequences. The bracovirus DNAs packaged in the particles were found to be amplified within more than 12 replication units. Strikingly, the nudiviral cluster, the genes of which encode particle structural components, was also amplified, although not encapsidated. Amplification of bracoviral sequences was shown to involve successive head-to-head and tail-to-tail concatemers, which was not expected given the nudiviral origin of bracoviruses
Sin-le-Noble, Le Raquet, tranche 15 (Nord)
LâamĂ©nagement de lâĂ©coquartier du Raquet par Douaisis Agglo sur la commune de Sin-le-Noble essentiellement, mais aussi Douai et Lambres-lez-Douai a donnĂ© lieu Ă de nombreuses opĂ©rations archĂ©ologiques depuis 2009. Ce sont ainsi plus de 120 ha qui ont pu ĂȘtre explorĂ©s et qui ont permis de mettre en valeur la structuration de ce micro-territoire depuis le NĂ©olithique jusquâĂ lâĂ©poque antique.Le projet de construction dâun boulodrome ainsi que la voirie conjointe a donnĂ© lieu Ă un diagnostic Ă lâautomne 2018. Celui-ci a permis de mettre au jour des vestiges datĂ©s de la pĂ©riode antique, notamment un bĂątiment sur fondation de craie damĂ©e, un four, des fossĂ©s, des fosses de rejets, mais surtout des fosses dâextraction de craie qui laissaient prĂ©sager lâexistence dâune carriĂšre. Le Service RĂ©gional de lâArchĂ©ologie des Hauts-de-France a ainsi dĂ©cidĂ© de prescrire une fouille sur une superficie de 14000 m2. La fouille a Ă©tĂ© exĂ©cutĂ©e du 5 juillet au 20 septembre 2019 et a permis de rĂ©fĂ©rencer 1874 UnitĂ©s dâEnregistrement, dont 22 faits, 193 nĂ©gatifs de creusement et 163 UnitĂ©s Artificielles.Sur lâemprise explorĂ©e, les premiĂšres traces dâoccupation remontent au Haut-Empire et sâillustrent par la prĂ©sence dâun vaste bĂątiment excavĂ©. Le matĂ©riel piĂ©gĂ© dans ses comblements date du Ier s. de n. Ăš. Peu dâautres vestiges peuvent ĂȘtre rattachĂ©s Ă cette pĂ©riode avec certitude. La parcelle semble ainsi abandonnĂ©e jusquâĂ la seconde moitiĂ© du IVe s. de n. Ăš. Sont rattachĂ©s Ă cette pĂ©riode un Ă©dicule associant une fosse et une semelle en craie damĂ©e, plusieurs chapelets de fosses, quelques fosses Ă©parses, un bĂątiment sur fondations de craie damĂ©e bĂąti en partie sur les comblements dâune carriĂšre Ă ciel ouvert qui a exploitĂ© la craie.Cette carriĂšre de craie sâĂ©tend sur environ 2 260 m2. Elle se compose en rĂ©alitĂ© de deux zones qui se sont succĂ©dĂ©es : la premiĂšre, Ă lâouest, Ă©tant abandonnĂ©e et comblĂ©e au moment oĂč la seconde, Ă lâest, Ă©tait exploitĂ©e. Chacune sâorganise en plusieurs grandes fosses qui sont creusĂ©es successivement, parfois jusquâĂ 5,40 m de profondeur. La nature de la craie sĂ©nonienne qui y a Ă©tĂ© extraite ne permet pas le façonnage de bloc destinĂ© Ă la construction. DĂšs lors, la craie extraite a ainsi pu servir Ă lâamĂ©nagement de fondations, Ă la fabrication de chaux, ou peut-ĂȘtre plus largement, Ă lâamendement des terres agricoles voisines. Si les niveaux qui la remplissent datent de la seconde moitiĂ© du IVe s. de n. Ăš., il nâest pas possible de dĂ©terminer lâĂ©poque Ă laquelle lâactivitĂ© dâextraction a dĂ©butĂ©.Deux systĂšmes dâenclos reprenant la mĂȘme trame parcellaire ont Ă©tĂ© identifiĂ©s. Cependant, lâindigence du matĂ©riel datant empĂȘche de les rattacher prĂ©cisĂ©ment Ă lâune ou lâautre des phases identifiĂ©es. Le systĂšme fossoyĂ© du nord-ouest est indĂ©niablement antĂ©rieur Ă lâinstallation de fosses qui ont Ă©tĂ© comblĂ©es durant la seconde moitiĂ© du IVe s., mais leur date dâimplantation nâest pas connue. Lâenclos mĂ©ridional nâest pas non plus datĂ© plus prĂ©cisĂ©ment que de la pĂ©riode gallo-romaine. Restant quasiment vide de structures au sein de son emprise, son calage chronologique, ainsi que son utilisation reste hypothĂ©tique. Plusieurs fours, un puits, un probable cellier, plusieurs segments de fossĂ©s ou palissades restent difficiles Ă©galement Ă caler chronologiquement dans lâorganisation de lâoccupation, tant les Ă©lĂ©ments marquants font dĂ©faut.Les limites dâemprise de lâopĂ©ration de fouille, la vision partielle de cette occupation ne permettent pas de caractĂ©riser prĂ©cisĂ©ment cette occupation, ou plutĂŽt ces occupations. Une portion dâun Ă©tablissement ayant existĂ© durant le Haut-Empire nous apparaĂźt au travers dâun vaste bĂątiment excavĂ© dont la fonction nous Ă©chappe et peut-ĂȘtre un systĂšme dâenclos fossoyĂ©. Dâautres vestiges lui sont sans doute contemporains, mais sans possibilitĂ© de le confirmer. Cette occupation se dĂ©veloppe certainement au nord ou Ă lâouest de lâemprise explorĂ©e, sans que lâon puisse identifier son statut. Les deux siĂšcles suivant le Ier s. nâont visiblement laissĂ© aucune empreinte matĂ©rielle, ce qui laisse penser que le site est complĂštement abandonnĂ©. AprĂšs un hiatus probable de plusieurs siĂšcles, les parcelles sont rĂ©occupĂ©es par une activitĂ© dâextraction de la craie. Il est nĂ©anmoins possible que cette activitĂ© ait commencĂ© plus tĂŽt. Mais cet Ă©lĂ©ment chronologique est impossible Ă apprĂ©hender dans lâĂ©tat de nos connaissances. Les nombreux Ă©lĂ©ments dâarchitecture (tegulae, fragments dâenduits peints, de mortier de tuileauâŠ) retrouvĂ©s rejetĂ©s dans les comblements des structures fouillĂ©es suggĂšrent clairement la proximitĂ© dâun Ă©tablissement ayant revĂȘtu un certain statut. Celui-ci dĂ©passe les limites de la fenĂȘtre dâobservation qui est la nĂŽtre. Comme cela est souvent constatĂ© pour le IVe s. dans nos rĂ©gions, lâoccupation du Bas-Empire semble rĂ©investir un Ă©tablissement dĂ©laissĂ© pour y mener une activitĂ© spĂ©cifique, ici lâextraction de craie
Towards a general synthesis of di-aza-amino acids containing peptides
International audienc