Replacing sperm with genotyped haploid androgenetic blastomeres to generate cattle with predetermined paternal genomes
Bibliographic record
Abstract
Although meiosis plays an essential role for the survival of species in natural selection, the genetic diversity resulting from sexual reproduction impedes human-driven strategies to transmit the most suitable genomes for genetic improvement, forcing breeders to select diploid genomes generated after fertilization, that is, after the encounter of sperm and oocytes carrying unknown genomes. To determine whether genomic assessment could be used before fertilization, some androgenetic haploid morula-stage bovine embryos derived from individual sperm were biopsied for genomic evaluation and others used to reconstruct "semi-cloned" (SC) diploid zygotes by the intracytoplasmic injection into parthenogenetically activated oocytes, and the resulting embryos were transferred to surrogate females to obtain gestations. Compared to controls, in vitro development to the blastocyst stage was lower and fewer surrogates became pregnant from the transfer of SC embryos. However, fetometric measurements of organs and placental membranes of all SC conceptuses were similar to controls, suggesting a normal post-implantation development. Moreover, transcript amounts of imprinted genes IGF2, IGF2R, PHLDA2, SNRPN, and KCNQ1OT1 and methylation pattern of the KCNQ1 DMR were unaltered in SC conceptuses. Overall, this study shows that sperm can be replaced by genotyped haploid embryonic-derived cells to produce bovine embryos carrying a predetermined paternal genome and viable first trimester fetuses after transfer to female recipients. SUMMARY SENTENCE: Haploid morula-stage embryonic cells derived from a single sperm can be genotyped and injected into activated oocytes to reconstruct diploid zygotes that develop both in vitro into blastocysts and in vivo into viable post-implantation bovine conceptuses with predetermined paternal genomes.
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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) | 0.003 | 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".