Size Specific Effects of Hyloronan (HA) on Sheep Blastocyst Formation and Quality In Vivo.
Bibliographic record
Abstract
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)
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".