In Vitro Maturation of Bovine Oocytes with Bovine Herpesvirus 5 Does Not Compromise the Subsequent Embryonic Development.
Bibliographic record
Abstract
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)
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".