Size Specific Effects of Hyloronan (HA) on Sheep Blastocyst Formation and Quality In Vivo.
Notice bibliographique
Résumé
Hyaluronan (HA) is a major component of the extracellular matrix. It has a critical role in various reproductive events including oocyte maturation, fertilization and embryogenesis. Through binding to its cell surface receptors (CD44 and RHAMM), HA involved in cell signalling, differentiation and proliferation. Hyaluronidase degrade HA into smaller HA fragments. The effect of HA has been shown to differ according to its size. We hypothesise that the size of HA fragments in the oviduct regulates early embryo development and affects embryo quality. To test this hypothesis, twenty cycling ewes were used. Oestrous cycles were synchronised using intravaginal sponges (Chronogest, Intervet, UK) for 12 days. Superovulation was induced on day 10 by combined injection of 700 U PMSG (Intervet UK Ltd) and 230U pFSH (Follitropin; Bioniche Animal Health, Belleville, ON, Canada). Ovulations were synchronised by a single injection of 8µg GnRH analogue (Receptal; Intervet) 24h after sponge removal. All ewes were naturally mated after onset of oestrous signs. Two days after mating, the oviducts of each animal were exposed by laparotomy and ligated at both ends. One oviduct was infused with Hyalovet-20 (5-7.5 x 105 Da, GE Healthcare, Amersham Place, UK) in the presence (n=10) or absence (n=10) of hyaluronidase (100 U/ml). In each treatment group, the contralateral oviducts were infused with saline (PBS; sigma) in the presence (n=5) or absence (n=5) of hyaluronidase (100 U/ml). Animals were slaughtered on day 7 after mating. The embryos were recovered from the oviducts and the stage of development was recorded. The quality of the blastocysts (cell count and apoptosis) was determined using differential staining combined with TUNEL labelling. The overall ovulation rate based on the number of corpora haemorrhagica on the day of the operation was 7.53 ovulation/ovary. The overall recovery rate was 213 embryo/271 ovulation (78.6%). The blastocyst rate in control oviducts was 37/67 (55.2%) and 5/37 (13.5%) of which were hatched. Infusion of oviducts with only hyaluronidase significantly increased (P<0.05) blastocyst rate (60/78; 76.9%) and percentage of hatched blastocysts (27/60; 45%). Hyalovet infusion both in the presence or absence of hyaluronidase did not affect blastocyst rate (17/40; 42.5% and 20/28; 71.4% respectively) or the hatching rate (5/17; 29.4% and 3/20; 15% respectively) compared to the control (P>0.05). Infusion with hyaluronidase increased the total and the TE cell numbers of blastocysts (211 ± 20.4 and 171 ± 19.3) compared to control(134 ± 8.2 and 97.5 ± 9.2; respectively, P>0.05). Number of apoptotic cells was not affected by any of the treatments. In conclusion, embryo development to blastocyst stage was improved in the presence of small HA fragments resulting from hyaluronidase degradation of endogenous HA. This was associated with increased TE cell count which may result in higher levels of interferon tau necessary for maternal recognition of pregnancy and improved pregnancy rate. Funded by BBSRC. (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 | 0,000 |
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 ».