154 THE EFFECT OF FIBROBLAST GROWTH FACTOR-4 ON THE DEVELOPMENT OF NUCLEAR TRANSFER BOVINE EMBRYOS
Bibliographic record
Abstract
Fibroblast growth factor-4 (FGF-4) has been shown to be preferentially produced in the inner cell mass (ICM) of mouse blastocysts, to stimulate the proliferation of mouse trophectoderm (TE) cells and to repress their transformation and differentiation into giant trophoblasts. Recent studies have shown that nuclear transfer (NT) bovine embryos have aberrant allocations of ICM and TE cells (Koo et al., 2002 Biol. Report. 67, 487–492) and aberrant expression of FGF-4 gene (Daniels et al., 2000 Biol. Reprod.63, 1034–1040). In this study, we examined whether recombinant human FGF-4 (rhFGF-4) stimulates development of nuclear transfer bovine embryos. As donor cells for NT, bovine ear skin fibroblast cells of passage 5 to 8 were used. Oocytes were enucleated after in vitro maturation in TCM 199 supplemented with 10% FBS, 1 µg mL-1 FSH and 1 µg mL-1 estradiol-17ß for 20 h. Enucleated oocytes were fused with donor cells by a DC pulse of 25 V/150 µm for 10 µs in Zimmerman cell fusion medium. For activation, fused oocytes were exposed to 10 µM Ca-Ionophore for 5 min, followed by 2 mM 6-dimethylaminopurine for 3 h. NT embryos were subsequently cultured in CR2 medium (containing 0.5% BSA) without or with rhFGF-4 (1, 10 and 100 ng mL-1) at 39.0°C in 5% O2, 5% CO2 and 90% N2. After 7 days of culture, blastocyst formation was observed. Apoptotic cells in blastocysts were detected by a terminal deoxynucleotidyl transferase-mediated d-UTP nick end-labeling (TUNEL) assay and total cell number was examined by propidium iodide (PI) counterstaining. Data were analyzed by chi-square test and Student’s t-test. Supplementation of serum-free medium with rhFGF-4 increased the proportion of embryos developing to the blastocyst stage (18.4, 29.4 and 23.5% for 0, 1 and 10 ng mL-1 FGF-4, respectively) and total cell number of blastocysts (66.3 ± 11.4, 75.9 ± 25.5 and 74.4 ± 22.4 for 0, 1 and 10 ng mL-1 FGF-4). Particularly, 100 ng mL-1 FGF-4 significantly (P < 0.05) increased the proportion of blastocysts (40.4%) and total cell number of blastocysts (86.7 ± 26.5) when compared with TCM 199 medium alone. FGF-4 also decreased the mean proportion of apoptotic cells in blastocysts (10.6 ± 7.8, 7.4 ± 5.3, 8.6 ± 5.3 and 7.5 ± 4.1% for 0, 1, 10 and 100 ng mL-1 FGF-4). Our results suggest that FGF-4 may play a role in the early development of NT bovine embryos and might be a useful molecule for increasing development of NT bovine embryos in serum-free culture systems.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.002 | 0.001 |
| 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".