246 IMPROVEMENT OF THE DEVELOPMENTAL CAPACITY OF OOCYTES FROM PREPUBERTAL CATTLE BY INTRAOVARIAN IGF-I APPLICATION
Bibliographic record
Abstract
The developmental potential of oocytes from prepubertal cattle is lower compared to their adult counterparts. Differences between oocytes from calves and cows have been found with regard to size, ultrastructural characteristics and metabolism. GH and IGF-I receptor mRNA have been identified in the cumulus cells and in oocytes (Izadyar F et al. 1997 Mol. Reprod. Dev. 47, 175–180; Armstrong D. et al., 2002 Reproduction 123 (6), 789–797). It is known that IGF-I and GH affect mRNA expression of glucose transporter 1 (Glut1) as well as glucose uptake by embryos. The goal of this study was to improve the developmental capacity of oocytes from prepubertal cattle and to determine whether an induced increase of GH and IGF-I levels affects the mRNA expression pattern of Glut1, UBF and eIF1A. Holstein calves (n = 30), 6–7 months old, were randomly divided into three groups. One group received a single s.c. injection of 500 mg of somatotrophin (rbST Posilac, Monsanto Company, St. Louis, MO, USA) and during the subsequent 2 weeks their follicles were aspirated 4 times via transvaginal ultrasound-guided ovum pick-up (OPU). The second group received an intraovarian injection of 6 µg rhIGF-I (R&D Systems, Wiesbaden-Nordenstadt, Germany). The third group served as control and received an intraovarian injection of 0.6 mL of 10 mM acetic acid. All animals were i.m. injected with 60 mg FSH (Folltropin®; Vetrepharm Inc., Ontario, Canada) 48 h prior to aspiration. The treatments were repeated with the same animal groups at the ages of 9–10, 11–12 and 14–15 months. Five adult cows were i.m. injected each with 100 mg FSH. For mRNA expression analysis (RT-PCR), embryos were collected with 2–4 cells, 8–16 cells and as blastocysts. The relative abundance of mRNA for Glut 1 and eIF1A was higher (P < 0.05) in 8–16 cell embryos from IGF-I-treated calves and cows than in control and rbST treated calves. The in vitro embryo production (IVP) results are shown in the Table 1. Our data show that IGF-I increased mRNA expression of Glut1 and eIF1A which may improve the developmental capacity of embryos produced from calves. Table 1 OPU/IVP-Results for calves (6–15 months old) in comparison with cows
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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".