Effect of Follicular Aging on the Nuclear Maturation and Distribution of Lipid Droplets in Bovine Oocytes.
Notice bibliographique
Résumé
Success of embryo transfer programs depends on optimal superstimulation and effects of the treatment on oocyte quality. Assessment of oocyte quality is based on resumption of meiosis (nuclear maturation) and redistribution of organelles within the ooplasm. Lipids act as important source for ATP generation through β-oxidation and poor quality oocytes tend to accumulate lipid droplets within ooplasm. Our objective was to study the effect of superstimulation protocols on nuclear maturation and distribution of lipid droplets in the ooplasm. We hypothesized that follicular aging after FSH starvation will result in maturation failure with accumulation of larger lipid droplets as compared to superstimulation with continued FSH support. Hereford heifers (n=12) were given prostaglandin F2a (PGF) to induce ovulation. Five days later, a progesterone releasing device (CIDR) was placed into vagina and transvaginal ultrasound-guided ablation of follicles was done to synchronize emergence of a new follicular wave. Next day (expected day of emergence of a new wave, Day 0), heifers were randomly allocated to three groups (n=4 each group). Heifers in standard FSH and FSH starvation groups were given 8 im injections of FSH (12-hour intervals) over 4 days, while those in long FSH group were given 14 im injections over 7 days. Two injections of PGF (at 12 hour interval) were given on Day 3 to the standard FSH group and on Day 6 to FSH starvation and long FSH groups. In all groups, CIDR was removed at second PGF and LH was given 24 hours later. Cumulus-Oocyte-Complexes were collected 18-20 hours post-LH by follicular aspiration. Oocytes were fixed and stained for nuclear maturation (Lamin/DAPI) and lipid droplets (Nile Red, 5 μg/ml). Oocytes were imaged with Zeiss LSM 710 confocal microscope. Oocyte volume sets were deconvoluted using Autoquant X2 and lipid droplets segmented using Imaris Pro 7.4.The proportion of mature oocytes were compared using Mantel-Haenszel Chi square test and lipid droplets data were compared using ANOVA. Long FSH group had greater proportion (59/100, 59%, P<0.01) of mature oocytes compared to standard FSH and FSH starvation groups (5/23, 21.7% and 2/25, 8.0%, respectively). The proportions of good (Grades 1 and 2) versus bad (Grades 3 and 4) oocytes in FSH starvation and long FSH treatments were not different (P=0.28) from that of standard FSH treatment. The FSH starvation and long FSH treatments did not cause significant changes in the total number (P=0.39) and total volume (P=0.58) of lipid droplets compared to standard FSH treatment. The percentage of lipid droplets in the peripheral ooplasm (10 μm distance from the ooplasmic membrane) of oocytes from FSH starvation and long FSH treatments did not differ from standard FSH treatment (50.1±2.7% and 40.4±3.8% vs 49.1±4.0%, P=0.66). Average volume of lipid droplets in oocytes was higher in FSH starvation group (11.5±1.5μm3, P=0.03) compared to standard FSH and long FSH groups (7.2±0.6μm3 and 8.0±0.8μm3). Average surface area of lipid droplets in oocytes was higher in FSH starvation group (20.3±1.5 μm2 P=0.04) compared to standard FSH group (14.6±1.1μm2) and was not different from long FSH group (17.1±1.1μm2). In conclusion, our hypothesis was supported in that FSH starvation caused maturation failure and accumulated larger lipid droplets in the ooplasm. Natural Sciences and Engineering Research Council of Canada funded
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) | 0,001 | 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 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 ».