Notice bibliographique
Résumé
Bedbugs (Cimex lectularius) have received a lot of attention lately for their role as a human parasite. But it turns out that bedbugs are involved with another interesting ecological interaction – their mutualism with the bacterium Wolbachia. And now a collaborative study with researchers from multiple institutions in Japan has unravelled the mechanism for how a bacterial infection can end up being mutually beneficial.The Wolbachia genus of bacteria infects a broad array of invertebrates, including nematodes, insects and spiders. Usually, it acts as a parasite, causing reproductive problems for its host. But in the bedbug, Wolbachia infection has positive effects on growth and reproductive output. Vertebrate blood (the bedbug's favourite meal) is low in B vitamins and bedbugs rely on their bacterial partner to synthesize them. Naruo Nikoh and his colleagues set out to investigate the origin of the relationship between these two odd bedfellows by examining the genome of the strain of Wolbachia, called ‘wCle’, that infects bedbugs.To test whether wCle was necessary for synthesis of vitamin B7 (biotin) and the development of bedbugs, the researchers raised bedbug nymphs on a diet of rabbit blood that was either supplemented with antibiotics (to produce wCle-free bedbugs) or unsupplemented (to produce bedbugs with a healthy population of wCle). In addition, they supplemented the diets of some of the nymphs with vitamin B7. Investigating the impact of each diet on the bedbugs and their bacterial lodgers, the team found that bedbugs that had a healthy wCle population had higher concentrations of vitamin B7 while bedbugs that had been cured of wCle infection and raised on rabbit blood without vitamin B7 were much less likely to survive to adulthood.After sequencing and assembling the wCle genome, the researchers examined the genes responsible for synthesizing B vitamins. They found that while most Wolbachia species have genes that can synthesize B2, as well as some of the genes necessary to synthesize vitamins B6 and B9, wCle can also synthesize vitamin B7. Also, the genes involved in vitamin B7 synthesis were extremely similar to those involved in the synthesis in other bacteria that live as endosymbionts. The researchers concluded that wCle may have received the genes through lateral gene transfer from one of these other species while infecting the same animal.Finally, they compared the genes of proteins involved in vitamin B7 synthesis in wCle with those in a Wolbachia species that infects the bedbug's closely related sister species Cimex japonicus, the bat bug. They found that the two sets of genes were almost identical, suggesting that the biotin synthesis genes were transferred to a Wolbachia strain and that it then infected the common ancestor of the bedbug and bat bug.Taken together, the authors think that the lateral transfer of vitamin B7 synthesis genes is the event that permitted wCle and bedbugs to strike up their symbiotic relationship. Although understanding that wCle makes bedbugs stronger might not be good news for humans worried about bedbugs sharing our homes, knowing how that relationship came about could help us understand the ecology of symbiosis a little better.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,002 | 0,002 |
| Science ouverte | 0,001 | 0,002 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,355 | 0,165 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».