============================================================ ~ Looking for a full-featured 401(k) plan? ~ ~ Success401k.Com is the answer for your growing business! ~ ~ Click below to learn more about an online 401(k) plan ~ http://click.topica.com/caaacz8b1ddNBb2HgmNb/Citibank ============================================================Cloning harbors serious, hidden problems, scientists say
By GARETH COOK �2001 THE BOSTON GLOBE
Since the birth of Dolly, the first cloned sheep, scientists have made
stunning progress, creating seemingly healthy copies of mice, pigs, goats and
cows.But Friday, almost five years to the day since Dolly's birth, a team of
scientists will announce evidence that these creations of modern science can
harbor serious hidden problems in their genetic code, raising new concerns
about plans to create a cloned human.The finding, reported in Friday's issue
of the journal Science, could explain why so many clone pregnancies fail, and
why some cloned animals suffer strange maladies in their hearts, joints and
immune systems. And the research, which focused on how cells interpret their
genetic instructions, suggests cloning causes further problems that have so
far evaded detection."There are almost no normal clones," declared study
author Rudolf Jaenisch, a professor of biology at MIT.The announcement comes
at a crucial time, with Congress considering sharp new limits on cloning
technology, and under pressure from a range of religious groups, biomedical
companies, and patients groups.Current cloning techniques could be used to
create a human clone -- a person, the report hints, who could have a host of
unpredictable medical and developmental problems. The same technology,
however, can also be used for "therapeutic cloning," a process that creates
healthy copies of a patient's cells -- not whole beings -- and could
eventually be used to treat diabetes, Parkinson's disease, and many other
disorders.Some geneticists worry that in the political fight over cloning,
these findings could become ammunition against not only human cloning, but
also therapeutic cloning."This is exactly the kind of paper that can be
misunderstood, stopping treatments that could save millions of people from
diseases," said Robert Lanza, vice president of research for Advanced Cell
Technology, a Worcester-based company that is heavily involved in cloning
research and could be put out of business by a broader ban.The authors of the
report investigated "gene expression," the vital process in which cells use
the parts of the genetic code they need. Different kinds of cells -- the
skin, muscles, nerves -- have different genes turned on. This pattern is what
determines the identity of the cell.To create a clone, researchers take a
cell -- a skin cell, say -- from an animal and then return the pattern of
gene expression to its most primitive setting, so it will behave like a
fertilized egg cell, ready to grow into a new animal.To accomplish this,
biologists transfer the DNA from one cell into an egg cell that has been
emptied of its own DNA. The egg cell then seems to reset the gene expression
of the injected DNA. From there it will grow into an embryo, and eventually a
live animal with a genetic code identical to that of the donor.But the reset
doesn't seem to work perfectly. In the research announced Friday, scientists
cloned mice and then compared the expression of six genes to normal mice. Of
about 40 mice, the vast majority had at least one abnormality, according to
another study author, David Humpherys of the Whitehead Institute and
MIT.Problems with gene expression can be completely harmless, or instantly
fatal, or somewhere in between. But with human cloning, the stakes would be
much higher."This may not be a critical fact in how a cow functions," said
Mark Westhusin, a leading cloning expert who is an associate professor at
Texas A&M. "But humans have to do more than stand out in a pasture and chew
grass."And because an animal has tens of thousands of genes, it would be
practically impossible to prove definitively that a particular clone is
normal, even if it appears fine at first. Dolly, for example, seemed
completely normal before suddenly turning obese.In this study, researchers
used embryonic stem cells, a primitive type of cell thought to be especially
easy to reprogram. Jaenisch said that the team plans to test clones made from
other cells, but expects to find similar problems.He emphasized that the
finding did not pose any problems for therapeutic cloning. In this technique,
a patient's cell is cloned, resetting it to its primitive state and then
allowed to divide for several days, to a pre-embryonic stage.This process
yields stem cells, which can then be turned into specialized cells that can
be implanted back into the patient. Because these cells are performing
specialized functions, small gene expression problems are less likely to pose
difficulties, the researchers said.Therapeutic cloning, though, has drawn
fire from religious and other groups who argue that the process is tantamount
to creating and then snuffing out a new life. Others fear it will make it
easier to create the world's first human clone.But "there is no reason to
punish innocent patients just because of the chance that someone might abuse
the system," said Lanza.Gareth Cook can be reached by e-mail at [EMAIL PROTECTED]
"We're not supposed to be perfect. We're supposed to be Useful."
Leonard Peltier
============================================================ Get FREE business cards for your business or personal use! VistaPrint.com is giving away 250 full color business cards - an $85 value. Claim this unique FREE gift now! http://click.topica.com/caaacASb1ddNBb2HgmNg/VistaPrint ============================================================
Visit and show your support for the Grass Roots Oyate http://members.tripod.com/GrassRootsOyate Clemency for Leonard Peltier. Sign the Petition. http://petitiononline.com/Release/petition.html
==^================================================================ EASY UNSUBSCRIBE click here: http://topica.com/u/?b1ddNB.b2HgmN Or send an email To: [EMAIL PROTECTED] This email was sent to: [email protected] T O P I C A -- Register now to manage your mail! http://www.topica.com/partner/tag02/register ==^================================================================
