Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Why Does Cloning Create Abnormalities? Scientists Take A Step Towards Finding Out


Significant abnormalities observed in cloned mice help reinforce the need to continue to avoid the reproductive cloning of humans, a scientist said on Wednesday 30 June 2004 at the 20th annual conference of the European Society of Human Reproduction and Embryology. Dr. Takumi Takeuchi, from Cornell University, New York, USA told a media briefing that he and Dr. Gianpiero Palermo’s team had compared imprinting abnormalities (the process where specific genes inherited from both parents are silent) in mice embryos derived from assisted reproduction techniques and from cloning.

“We found significantly impaired development in the cloned embryos compared with those derived from more conventional ART techniques”, said Dr. Takeuchi, “and this has made us more convinced that reproductive cloning is unsafe and should not be applied to humans.”

Drs. Takeuchi and Palermo were prompted to undertake the research by concerns about the increased incidence of imprinting abnormalities in children born after ARTs. The most prominent of these is Beckwith-Wiedemann syndrome, where children are born larger than normal.

Scientists also knew that cloned animals had been born with a similar condition, called ‘large offspring syndrome’. Dr.Takeuchi’s team set out to study whether the disorders arising in the ART system and those in cloned animals were comparable. The team took mouse oocytes and divided them into three groups. 68 were inseminated by ICSI, 37 activated parthenogenetically (without involving male gametes), and 77 were cloned by injected a cell nucleus into an egg where the nucleus had been removed. Of this latter group, 43 underwent first embryonic cleavage (the first few divisions of an embryonic egg) and 15 became full blastocysts.

“The embryos created by parthenogenesis and those from ICSI reached the blastocyst stage at the same rate, unlike the clones, where only 30% got that far”, said Dr. Takeuchi. “This appears to be due to the abnormal gene expression we saw in the cloned group. This not only explains the developmental impairment of the cloned group, but may in future be helpful in identifying environmental culture condition that are deleterious to the development of ART embryos,” he said.

Dr. Takeuchi said that as yet it was difficult to make a direct link with a specific cause for the abnormalities. “But there are a number of possibilities”, he said. “They could be linked to fertility medications utilized to induce superovulation, or the progesterone employed to help implantation; in vitro culture conditions which could be related to the length of the culture or the concentrations of certain media components such as serum or even a specific amino acid. Finally, we cannot exclude the contribution of the peculiar genetic makeup of patients’ gametes, together with the specific ART procedure”, he said.

Identification of gene expression abnormalities would help to monitor the development of reproductive techniques prior to their application to routine medical practice, said Dr. Takeuchi.

Emma Mason | alfa
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>