HOME >> BIOLOGY >> NEWS
Gene thats key to cloning success also hints at serious hurdles to reproductive cloning

PHILADELPHIA -- Scientists at the University of Pennsylvania have found that the activity of a single gene is a powerful predictor of whether newly cloned mammalian embryos will survive and thrive, but the genes sporadic expression in cloned mouse embryos casts fresh doubt on prospects for reproductive human cloning.

The findings, by a team led by K. John McLaughlin and Hans R. Schler of Penns School of Veterinary Medicine, are described in the May 15 issue of the journal Genes & Development.

Despite the successful cloning of sheep, pigs and cats, mammalian cloning -- in which an ordinary cells nucleus is transferred to an egg whose nucleus has been removed -- remains remarkably inefficient. Fewer than three in 100 cloned mouse embryos survive to birth.

McLaughlin and Schlers group showed that the activity of the gene Oct4 correlates strongly with the viability of cloned embryos but also found that in only one-tenth of cloned mouse embryos is the gene expressed at the right level in the right place at the right time. Without Oct4, embryos cannot survive; even if Oct4 expression is a tad high or low, an embryo will die.

"Cloning requires the precise reprogramming of the nucleus inserted into an enucleated egg," said Schler, professor of animal biology and director of Penns Center for Animal Transgenesis and Germ Cell Research. "This nucleus must abandon its former genetic program and adopt the genetic profile of an embryonic nucleus; failure to do so dooms the embryo."

To evaluate the accuracy of this genetic reprogramming, The Penn group analyzed Oct4 expression in cloned mouse embryos derived from cells that surround ovulated eggs in adult mice, cells that would not normally express Oct4. The result: Only 34 percent of embryonic cells correctly reprogrammed to express Oct4, and just 10 percent showed levels of Oct 4 expression conducive to further development.

Even as it suggests new hurdles for reproductive
'"/>

Contact: Steve Bradt
bradt@pobox.upenn.edu
215-573-6604
University of Pennsylvania
14-May-2002


Page: 1 2

Related biology news :

1. Malignant cancer cells generate mice through cloning
2. Stem-cell research and reproductive cloning laws should be separate
3. Therapeutic cloning no longer a dream, says scientist who produced first cloned embryonic stem cell
4. Why does cloning create abnormalities? Scientists take a step towards finding out
5. Therapeutic cloning may be permitted at Newcastle University
6. Landmark conference for United Nations on human cloning and stem cell research
7. Scientists develop new cloning technique that dramatically shortens the search for genes
8. Equine clonings triple play sheds light on calcium, cell signaling, human disease
9. Advances in equine cloning may aid insight into human diseases
10. International scientific body calls for ban on human reproductive cloning
11. Research shows therapeutic cloning can cure Parkinsons-like disease in mice

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:1/20/2019)... ... January 17, 2019 , ... ... metabolism and distribution has been documented for many years. These observed differences may ... of adverse event profiles in patients residing in different geographic regions. This created ...
(Date:1/14/2019)... SUNNYVALE, Calif. (PRWEB) , ... January 14, 2019 ... ... a proprietary technology to detect precancer and cancer cells in blood, will present ... revealing significant advancement in the fight against colorectal cancer. The results from this ...
(Date:1/10/2019)... Va. (PRWEB) , ... January 09, 2019 , ... Dr. ... Ottawa Heart Institute in Ottawa, Ontario, Canada. He is also Director of its ... Department of Medicine, in the Department of Radiology, and in the Department of Cellular ...
Breaking Biology News(10 mins):
(Date:1/20/2019)... ... 17, 2019 , ... Consumers are directing healthcare in many ... That's changing as many services now exist for patients to order tests without ... $208 million in 2018, according to Kalorama Information’s new report, The Direct-To-Consumer ...
(Date:1/15/2019)... ... 2019 , ... Personalized treatment plans may extend life expectancy for early-stage kidney ... study published in the journal Radiology. , Kidney, or renal, tumors are often ... procedure in which the tumor and part of the kidney are removed. However, some ...
(Date:1/10/2019)... ... January 08, 2019 , ... Rascal was adopted from a local shelter when he was ... mixed breed.” Unfortunately, just six weeks after he was adopted, he tore his right ... to form in the joint after such a traumatic injury. , Sure enough, when Rascal ...
(Date:1/8/2019)... ... January 08, 2019 , ... The American Society of Gene ... named by a selection committee made up of industry leaders identified by the ASGCT ... grants are mentored awards created to support ASGCT members designing transformative pilot studies in ...
Breaking Biology Technology:
Cached News: