92 INSULIN-LIKE GROWTH FACTOR-1 PROTECTS BOVINE PRE-IMPLANTATION EMBRYOS PRODUCED IN VITRO FROM ANTI-DEVELOPMENTAL ACTIONS OF MENADIONE
Bibliographic record
Abstract
The objective of this study was to evaluate the protective effect of insulin-like growth factor (IGF-1) on blastocyst development and cryotolerance of bovine embryos in in vitro culture (IVC) under oxidative stress induced by menadione (MD). Cumulus-oocyte complexes (n = 1421) were matured in TCM-199 with bicarbonate, hormones, and 10% FCS for 22 h. After fertilization, the presumptive zygotes were cultured up to 7 days in SOF medium with 2.5% FCS and 0.5% BSA (control), and also supplemented with 100 µM IGF-1 (IGF). At Day 6, MD was included in the culture medium (0 µM, control; or 5.0 µM, MD) during 24 h. Cultures were conducted at 38.5°C in 5% CO2 in air. The cleavage and blastocysts rates were evaluated, respectively, at Days 3 and 7 (IVF = Day 0). At Day 7, a sample of the blastocysts was stained with 5 µM H2DCFDA (Molecular Probes, Canada) to evaluate the intracellular ROS levels or was stained for TUNEL (In Situ Cell Death Detection Kit, Roche, Indianapolis, IN, USA). Stained embryos were immediately evaluated under an epifluorescence microscope (excitation 495/550 nm and emission 404/590 nm, respectively, for ROS and TUNEL), and the images of embryos stained with H2DCFDA were analysed by Q-Capture Pro image software for determining the fluorescent intensity. Other blastocysts were vitrified (Ingámed®, Maringá-PR, Brazil), and after warming, they were cultured for 24 h to evaluate the re-expansion rates. The results were compared by ANOVA followed by Student’s t-test (mean ± s.e.M) and re-expansion rates by chi-square test (P < 0.05). The cleavage rates did not differ (P > 0.05) among groups (77.1 ± 1.9% to 82.75 ± 2.2%). The blastocyst rates were similar between control (35.4 ± 2.0%) and IGF (34.5 ± 3.7%), and both were higher (P < 0.05) than MD (21.3 ± 2.7%); the IGF+MD group (28.3 ± 1.6%) was similar (P > 0.05) to all groups. The intracellular levels of ROS were higher (P < 0.05) for the MD group (21.7 ± 0.7) than for control (17.0 ± 1.6), and both were similar (P > 0.05) to the IGF (19.2 ± 0.6) and IGF+MD (18.0 ± 1.0) groups. The highest rates of apoptosis were found in the MD group (22.3% ± 2.3) and the smallest in IGF (9.1% ± 0.7), and both differed (P < 0.05) from control (12.8% ± 1.0), and IGF+MD (15.6% ± 1.6). The re-expansion rates were similar between control (77.4%) and IGF (69.2%), and both were higher (P < 0.05) than MD (49.1%); however, the IGF+MD group (57.6%) was similar (P > 0.05) to IGF and MD groups. In conclusion, the supplementation with IGF-1 during IVC reversed the detrimental effects of MD on embryonic levels of ROS and apoptosis, as well as improved the embryo development and cryotolerance of blastocysts under oxidative stress. Financial support was provided by FAPESP (#2012/10083–8 and #2013/07382–6).
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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".