en.wikipedia.org/wiki/Zhong_Zhong_and_Hua_Hua
3 corrections found
the donated nuclei came from fetal cells, not embryonic cells.
This contrast is inaccurate. Earlier monkey nuclear-transfer experiments also used fetal cells, including fetal fibroblasts, not just embryonic cells.
Full reasoning
The sentence says earlier monkey-cloning attempts used embryonic cells, whereas Zhong Zhong and Hua Hua were different because their donor nuclei came from fetal cells. But a 2002 rhesus-monkey nuclear-transfer study explicitly states that researchers tested both embryonic blastomeres and fetal fibroblasts (somatic cell NT).
So fetal donor cells were not unique to the Zhong Zhong/Hua Hua work. What was new in 2018 was successful live birth from SCNT in this primate species—not the mere use of fetal donor nuclei.
2 sources
- Rhesus monkey embryos produced by nuclear transfer from embryonic blastomeres or somatic cells - PubMed
The objective of this study was to determine the developmental competence of nuclear transfer (NT) embryos derived from embryonic blastomeres (embryonic cell NT) or fetal fibroblasts (somatic cell NT) as a first step in the production of rhesus monkeys by somatic cell cloning.
- Assisted reproductive technologies in rhesus macaques - PMC
In monkeys, we began efforts to produce animals by nuclear transfer ... We repeated this success in 2002 ... The most likely cause of death was fetal asphyxia ... we concluded that fetal demise was unrelated to the nuclear transfer process.
They then placed 21 of these ova into surrogate mother monkeys
The number 21 refers to surrogate monkeys, not ova. Reports on the experiment say 79 embryos were implanted into 21 surrogate mothers.
Full reasoning
This sentence mixes up the number of surrogates with the number of eggs/embryos transferred. Contemporary reporting on the Cell paper states that the researchers created 109 embryos from fetal tissue, implanted 79 of them into 21 surrogates, and got six pregnancies leading to Zhong Zhong and Hua Hua.
So 21 was the number of surrogate mothers, not the number of ova placed into them.
2 sources
- These baby monkeys are first cloned primates created using the Dolly method - Ars Technica
Next, the researchers tried using DNA from fetal tissue. They created 109 embryos, implanted 79 of them into 21 surrogates, leading to pregnancy in six of them. Two female monkeys, Zhong Zhong and Hua Hua, resulted.
- Cloning of Macaque Monkeys by Somatic Cell Nuclear Transfer
For SCNT using fetal monkey fibroblasts, 6 pregnancies were confirmed in 21 surrogates and yielded 2 healthy babies.
the first cloned mammal Dolly the sheep
Dolly was not the first cloned mammal overall. She was the first mammal cloned from an adult cell.
Full reasoning
This wording drops an important qualifier. Dolly was historically significant because she was the first mammal cloned from an adult somatic cell, not the first cloned mammal of any kind.
The Roslin Institute—the institution that created Dolly—explicitly says: "Dolly was the first mammal to be cloned from an adult cell. However, Dolly was not the first ever cloned mammal." Guinness World Records likewise describes Dolly as the first animal cloned from an adult cell. So the article's broader phrasing is inaccurate.
2 sources
- The Life of Dolly | The Roslin Institute
Dolly was the first mammal to be cloned from an adult cell. However, Dolly was not the first ever cloned mammal.
- First animal cloned from an adult cell | Guinness World Records
A Finn Dorset sheep called Dolly ... was the first animal to be successfully cloned from an adult cell.