53 MODIFIED AIR-DRY METHOD REVEALS THAT DIPLOID CELLS ARE PREDOMINANT IN CLONED BOVINE EMBRYOS
Bibliographic record
Abstract
Chromosomal analysis is important for evaluating embryo quality. Reports on the cytogenetic analyses of bovine nuclear transfer (NT) embryos, however, have varied according to methods used (Mohamed NMS et al. 2000 J. Vet. Med. Sci. 62, 339–342; Arat S et al. 2002 Biol. Reprod. 66, 1768–1774; Booth PJ et al. 2003 Biol. Reprod. 68, 922–928). An improved air-dry method was developed in this study to specifically investigate the chromosomal composition of bovine NT embryos. NT embryos were obtained by transferring cumulus cells into enucleated oocytes, the fused embryos were then co-cultured in CR1aa with bovine cumulus cells. Day 5 embryos were cultured in the presence of 0.01µg mL-1 colcemid for 18 h (classical method is 5 h) and then in 1% sodium citrate for 3 to 5 min (classical method is 15 to 30 min), and fixed on slides, total of 55 embryos were analyzed. The categories for the chromosome composition were classified as follows: diploid (2n), triploid (3n), tetraploid (4n), mixoploid (including 2n/3n, 2n/4n, and 2n/3n/4n). Any embryo that did not show an interpretable metaphase spread due to gross overspreading or clumped chromosomes was not classified. The mitotic index (number of metaphase plates/total cell number of analyzed embryo) was 41.1% (700/1701), which is significantly higher (P < 0.001) than that obtained by the classical method (11.9%, 50/419). Of 700 metaphase plates observed, 608 (86.9%) were diploid. Triploidy and tetraploidy were 49 (7%) and 42 (6%), respectively. There were 72.7% (40/55) of the embryos diploid, and 27.3% (15/55) polyploid or mixploid, which included 3n (1/15), 4n (1/15), 2n/3n (5/15), 2n/4n (3/15), and 2n/3n/4n (4/15). Of the 15 non-diploid embryos, 64% of the total cells were diploid. The results of this study indicate that diploidy is the predominant state in bovine Day 5 NT embryos.
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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 | 0.001 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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".