In Vitro Maturation of Bovine Oocytes with Bovine Herpesvirus 5 Does Not Compromise the Subsequent Embryonic Development.
Notice bibliographique
Résumé
Bovine Herpesvirus 5 (BoHV-5), an etiological agent of bovine encephalitis, has a great genomic similarity to BoHV-1. The latter, in turn, has been found in cumulus-oocyte complexes, follicular fluid, granulosa cells and uterine tubal cells. On the other hand, there is no report on the presence of BoHV-5 in reproductive cells and fluid. The objective of this study was to evaluate the effects of contamination of bovine oocytes during in vitro maturation (IVM) by BoHV-5 and the subsequent embryonic development. Selected oocytes, obtained from ovaries at a local slaughterhouse, were washed in PBS with 10% FCS (Nutricell, Campinas, Brazil) free of virus contamination, and then transferred to drops (100 μl) of maturation medium (MM), consisting of TCM 199 (GIBCO, Grand Island, USA), 2.2 mg/ml sodium bicarbonate, 0.02 mg/ml sodium pyruvate, 0.05 mg/ml gentamicin sulfate, 0.5 μg/ml FSH (Pluset, Calier, Spain) and 50 μg/ml LH (Lutropin-V Bioniche Inc., Canada). The oocytes were assigned into two experimental groups: I (control: without virus) and II (with virus; 10-2 TCID50/ml). After a 1h viral co-incubation interval at 39°C and 5% CO2 in air, immature oocytes were washed and matured in drops of MM (devoid of virus) for additional 23 h. For in vitro fertilization, semen was thawed and centrifuged at 700 x g for 30 minutes in Percoll gradient. Afterwards, the pellet was re-suspended in TALP, centrifuged (200 x g for 5 minutes), and further diluted in the same medium, but supplemented with PHE and heparin. Then, gametes were co-incubated for 20 h. The embryo culture was carried out in modified SOF up to day 7 post-insemination (pi). The insemination period and embryo culture were under the same conditions previously reported for IVM. The fertilization rates and percentages of oocytes that reached morula (M)/blastocyst (B)/ expanded blastocyst (EB) and B/EB/hatching blastocyst (HB) stages were recorded at 72, 144 and 168 h pi, respectively. Data of 9 replicates were analyzed using t-test for independent samples with P <0.05 taken as significant. The in situ hybridization (ISH) assay was performed in order to detect the DNA viral in matured oocytes and in vitro derived embryos. In this experiment, BoHV-5 contamination was detected in both oocytes and embryos, but the results of fertilization rates (89.9 vs. 87.1) and percentages of produced embryos (M/B/EB; 31.1 vs. 32.1 and B/EB/HB; 28.2 vs. 29.9) were not significantly different between groups. Thus, the introduction of BoHV-5 during in vitro oocyte maturation resulted in production of contaminated embryos, but this infection did not compromise their development as evidenced by the similar rates of yielded embryos. However, sanitary risks associated with the transmission of BoHV-5 via contaminated embryos should be taken in consideration and, therefore, sanitary control measures are important to prevent the virus dissemination. Acknowledgements: FAPESP (07/57774-7) and BrasFrigo, Birigui, Brazil. (poster)
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 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,001 |
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 ».