Korea pushes forward on cloning front
http://www.100md.com
《英国医生杂志》
A team led by Hwang Woo-suk, professor of the college of veterinary medicine at Seoul National University, has successfully cloned a dog using somatic cell nuclear transfer. The Afghan hound puppy, named Snuppy, was born on 24 April and was one of only two live births from the 1095 eggs that were harvested. The second dog died as a result of aspiration pneumonia after 22 days.
Professor Hwang's team collected 1500 eggs from 123 surrogates and transferred 1095 eggs back to the same dogs. The cloning process presented unique technical challenges because canine eggs are not mature at ovulation and continue the process of maturation in the oviduct. The research was published in Nature ( 2005;436: 641).
"With more than 400 dog breeds displaying remarkable behavioural traits and diverse disease predilections, canine nuclear transfer holds promise for both veterinary and human health discoveries," said Professor Hwang.
"Canine genome studies may have wide ranging applications and canine nuclear transfer may enable in vitro studies while reducing animal requirements. If canine embryonic stem cells are established, it would provide another therapeutic cloning model so that perhaps man's best friend might be among the first beneficiaries of immune-matched stem cell transplantation," he said.
Critics of Professor Hwang's work say that the low success rate severely detracts from the value of the research and that successful cloning of dogs may pave the way for human reproductive cloning. However, Professor Hwang says that efficiency will improve as the research continues and questions the validity of the latter claim on both ethical and scientific grounds.
"We are strongly against human reproductive cloning must be banned all over the world. The characteristics of domestic animals' oocytes are very different from those of humans. The reproductive physiology morphology of the oocytes varies according to the species. Due to this difference, it is almost impossible to clone humans at this stage of the research," he said.
In February this year Professor Hwang's team announced it has successfully cloned human embryos and extracted embryonic stem cells from them, and work is continuing in this area.
At the same time, a Korean biotechnology company, Maria Biotech, has been granted a licence to grow human stem cells from frozen embryos to produce specific cells or organs.
Whereas Professor Hwang was granted permission to do stem cell research on an exceptional basis, Maria Biotech's licence is the first to be granted since the country's bioethics laws came into force on 1 January 2005.
Park Se-pill, director of Maria Infertility Hospital Medical Institute and Maria Biotech, successfully isolated human stem cells from frozen embryos in 2000. "The Korean government has approved our application for research on growing human stem cells into specific cells or organs. Our research plan is to study animal model diseases such as Parkinson's disease, spinal cord injury, spinal open neural tube defects, and so on," said Dr Park.(Jane Parry)
Professor Hwang's team collected 1500 eggs from 123 surrogates and transferred 1095 eggs back to the same dogs. The cloning process presented unique technical challenges because canine eggs are not mature at ovulation and continue the process of maturation in the oviduct. The research was published in Nature ( 2005;436: 641).
"With more than 400 dog breeds displaying remarkable behavioural traits and diverse disease predilections, canine nuclear transfer holds promise for both veterinary and human health discoveries," said Professor Hwang.
"Canine genome studies may have wide ranging applications and canine nuclear transfer may enable in vitro studies while reducing animal requirements. If canine embryonic stem cells are established, it would provide another therapeutic cloning model so that perhaps man's best friend might be among the first beneficiaries of immune-matched stem cell transplantation," he said.
Critics of Professor Hwang's work say that the low success rate severely detracts from the value of the research and that successful cloning of dogs may pave the way for human reproductive cloning. However, Professor Hwang says that efficiency will improve as the research continues and questions the validity of the latter claim on both ethical and scientific grounds.
"We are strongly against human reproductive cloning must be banned all over the world. The characteristics of domestic animals' oocytes are very different from those of humans. The reproductive physiology morphology of the oocytes varies according to the species. Due to this difference, it is almost impossible to clone humans at this stage of the research," he said.
In February this year Professor Hwang's team announced it has successfully cloned human embryos and extracted embryonic stem cells from them, and work is continuing in this area.
At the same time, a Korean biotechnology company, Maria Biotech, has been granted a licence to grow human stem cells from frozen embryos to produce specific cells or organs.
Whereas Professor Hwang was granted permission to do stem cell research on an exceptional basis, Maria Biotech's licence is the first to be granted since the country's bioethics laws came into force on 1 January 2005.
Park Se-pill, director of Maria Infertility Hospital Medical Institute and Maria Biotech, successfully isolated human stem cells from frozen embryos in 2000. "The Korean government has approved our application for research on growing human stem cells into specific cells or organs. Our research plan is to study animal model diseases such as Parkinson's disease, spinal cord injury, spinal open neural tube defects, and so on," said Dr Park.(Jane Parry)