Two monkeys successfully cloned using same technique as Dolly the Sheep
Two monkeys have been cloned in China using the same technique that saw Dolly the Sheep cloned in Scotland.
The successful cloning of the two monkeys has raised concerns about the ethics of genetic engineering.
Two cynomolgus monkeys were successfully cloned by somatic cell nuclear transfer (SCNT) which could lead to the creation of hundreds of identical primates.
In the study, improved blastocyst development and pregnancy rate of transplanted SCNT embryos in surrogate monkeys were identified.
Six pregnancies were confirmed in 21 surrogates and yielded two healthy babies.
Dr. Calum MacKellar, an expert in Bio-ethics, says such cloning has implications for human cloning.
"Even 20 years ago when Dolly the sheep was created I remember there was a doctor based in America who tried to develop a clinic where cloning would be possible," he said.
The figure above from the journal, The Cell shows the procedure for Monkey SCNT Using Fetal Monkey Fibroblasts.
- (A) Fetal monkey fibroblasts in primary culture.
- (B and C) Spindle-chromosome complex (arrowhead) in a monkey MII oocyte before (B) and after (C) removal.
- (D–F) An oocyte with a slit in the zona pellucida (D, arrowhead) induced by laser irradiation, and the HVJ-E-incubated fibroblast (arrowhead) before (E) and after (F) injection into the perivitelline space.
- (G) Spindle-like structure formed by the donor fibroblast nucleus after fibroblast-cytoplast fusion.
- (H) Single nucleus formed after embryo activation with ionomycin and DMAP.
- (I) Blastocysts developed from Kdm4d mRNA-injected embryos, which were produced by SCNT using fetal fibroblasts (arrowheads: ICM).
- (J–L) Example images of blastocysts with and without normal development of ICM shown at a higher resolution. Blastocysts with a prominent ICM (arrowhead) obtained by SCNT (J), blastocysts with a prominent ICM (arrowhead) obtained by ICSI (K), and poor-quality blastocysts without clear ICM obtained by SCNT (L).
Cloning of animals by somatic cell nuclear transfer (SCNT) has been achieved in 23 mammalian species, including sheep, mice, cattle, pigs, cats, rats, and dogs.
