The cloning of a frog.
Level 5 - mechanism / opinion, no new human data
Historical commentary and retrospective essay (Level 5 by design analogy, non-clinical CEBM)
PubMed 23715536 · doi:10.1242/dev.097899
What was done
The author provides an invited historical commentary reflecting on his landmark 1962 single-author publication in the Journal of Embryology and Experimental Morphology (now Development), which demonstrated nuclear transfer in amphibians and formed the basis for a subsequent Nobel Prize in Physiology or Medicine.
What was found
The abstract contains no empirical data or quantitative metrics. It notes the focus of the original 1962 study: producing normal Xenopus laevis tadpoles from the nuclei of intestinal epithelium cells.
Why it matters
This commentary provides historical context on the discovery that differentiated cell nuclei retain the full developmental potential to generate viable organisms.
Limits
This is a single-author historical commentary rather than a primary research study or systematic review. No new experimental data, sample sizes, or quantitative analyses are reported.
Cited by
- supports John Gurdon demonstrated that cellular aging and genomic programming can be reset by transferring an adult tadpole cell nucleus into an enucleated frog egg to generate a new tadpole.