Featured Research

from universities, journals, and other organizations

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

Date:
July 2, 2004
Source:
European Society For Human Reproduction And Embryology
Summary:
Significant abnormalities observed in cloned mice help reinforce the need to continue to avoid the reproductive cloning of humans, a scientist said today (Wednesday 30 June 2004) at the 20th annual conference of the European Society of Human Reproduction and Embryology.

Berlin, Germany -- Significant abnormalities observed in cloned mice help reinforce the need to continue to avoid the reproductive cloning of humans, a scientist said today (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.


Story Source:

The above story is based on materials provided by European Society For Human Reproduction And Embryology. Note: Materials may be edited for content and length.


Cite This Page:

European Society For Human Reproduction And Embryology. "Why Does Cloning Create Abnormalities? Scientists Take A Step Towards Finding Out." ScienceDaily. ScienceDaily, 2 July 2004. <www.sciencedaily.com/releases/2004/07/040701085957.htm>.
European Society For Human Reproduction And Embryology. (2004, July 2). Why Does Cloning Create Abnormalities? Scientists Take A Step Towards Finding Out. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2004/07/040701085957.htm
European Society For Human Reproduction And Embryology. "Why Does Cloning Create Abnormalities? Scientists Take A Step Towards Finding Out." ScienceDaily. www.sciencedaily.com/releases/2004/07/040701085957.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins