199 PREMATURATION OF BOVINE OOCYTES WITH BUTYROLACTONE I AND/OR CILOSTAMIDE: EFFECTS ON MEIOSIS PROGRESSION, CYTOPLASMIC MATURATION AND GENE EXPRESSION
Notice bibliographique
Résumé
Meiotic block during a prematuration culture (pre-IVM) before in vitro maturation (IVM) is suggested as a way to provide additional time to synchronize oocyte-somatic cell communication, leading to improved cytoplasmic maturation and nuclear meiotic competence and the acquisition of critical cellular functions necessary for developmental competence. This study was designed to evaluate the effects of the inhibitors butyrolactone I (Bl-I) and cilostamide on oocyte nuclear and cytoplasmic maturation. For that, 2 well-established methods of pre-IVM and IVM for cilostamide (Albuz et al. 2010 Hum. Reprod.25, 2999–3011) or Bl-I (Hashimoto et al. 2002 Biol Reprod.66, 1696–1701) were used. Abattoir-collected oocytes were IVM in maturation medium (MM: mSOF with 0.8% BSA and hormones) for 24 h, without a previous pre-IVM culture (control). Cilostamide-group oocytes were treated for the first 2 h in vitro (pre-IVM) with 100 µM of the adenylate cyclase activator forskolin and 500 µM IBMX (nonspecific phosphodiesterase inhibitor) and then oocytes underwent extended IVM for 30 h in the presence of 20 µM cilostamide (type 3 phosphodiesterase inhibitor; pre-IVM 2 h + IVM 30 h). The Bl-I-group oocytes were pre-IVM for 24 h with 100 µM Bl-I diluted in TCM-199 supplemented with 0.2 mM pyruvate and then were IVM in MM for 20 h (pre-IVM 24 h + IVM 20 h). The Bl-I + Cilost group was a combination of both procedures: oocytes were first pre-IVM with Bl-I for 24 h and then cultured as described for the cilostamide group (pre-IVM 24 h + IVM 30 h). Cultures were carried out at 38.5°C in 5% CO2 in humidified air. After IVM, oocytes were stained with 500 nM mitotracker red to assess the mitochondrial membrane potential (??m) and with 10 µg mL–1 of Hoescht 33342 to evaluate the nuclear maturation (n = 207). Images were captured by an Olympus confocal microscope and analyzed with Fluoview software. The TUNEL assay was used to detect oocyte DNA fragmentation (n = 74). Relative amounts of mRNA for apoptotic-related genes were quantified after IVM in individual oocytes using real-time PCR (Kameyama et al. 2007 Reproduction133, 423–32). Means were compared by ANOVA and Tukey's test or by chi-square (P = 0.05). The percentage of oocytes reaching metaphase II after IVM did not differ among groups (73.8 to 90.4%; P = 0.05), indicating that in vitro meiotic resumption was normal. The ??m, expressed in arbitrary units of fluorescence, was 1.0 ± 0.1a (control), 2.7 ± 0.4b (Bl-I), 3.2 ± 0.5b (Cilost) and 2.1 ± 0.3ab (Bl-I + Cilost). The percentage of TUNEL-positive oocytes (18.8–41.3%) did not differ among groups (P = 0.05). The relative abundance of BAX (1.0 ± 0.4 to 2.3 ± 0.4) and BCL-XL (1.0 ± 0.3 to 0.3 ± 0.1) transcripts was unaffected by pre-IVM and IVM (P = 0.05). In conclusion, except for an increase in mitochondrial activity, pre-IVM with cilostamide and/or Bl-I did not affect cytoplasmic and nuclear oocyte maturation. However, oocyte developmental potential needs to be better evaluated in a future study through assessment of embryonic development. We acknowledge FAPESP and NSERC.
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Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 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) | 0,000 | 0,000 |
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 tête enseignante, 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 ».