Tag Archive | "mitochondria disease"

Tags: , , , , , , , , ,

Chimeras for Transplant Organs and Third Parent Immunity

Posted on 13 August 2013 by Jerry

How you feel about something may be a function of how broadly you generalize or how narrowly you define it.  We have two scientific situations that specifically sound positive and yet generally may set disturbing precedents.  Each of us should decide how general we think we should be, what are the downsides and who determines outcomes.

In Japan there is a partial governmental ban on experiments that create chimeras, or mix human cells with cells of other animals to create cross species hybrids.  Creation of chimeras is permitted in vitro, a test tube or petri dish involving just cells, for up to fourteen days after which the resulting cells are destroyed.  No experiments are permitted in vivo, or with a whole living organism.

It is just such a whole living organism experiment that has been proposed by Dr. Hiromitsu Nakauchi, a stem cell biologist at the University of Tokyo.  He believes he can grow human organs in a pig fetus by implanting human pluripotent stem cells into a genetically engineered pig fetus that lacks a specific organ.

An article appearing in the June 28, 2013 issue of Science magazine states “Mouse experiments have shown that pluripotent cells can fill the developmental niche opened by the absence of an organ.”  Dr. Nakauchi believes he can eliminate the fear of organ rejection by using the recipient’s own pluripotent cells to be grown in the pig.  After the piglet is born, when the organ is the right size, it would be harvested and transplanted into the human being.

While having received a Japanese government ethics panel endorsement, Dr. Nakauchi will probably wait no longer.  He has just been awarded a $6.2 million grant from the California Institute for Regenerative Medicine and is in discussions to open a new lab at Stanford University.  The California Institute for Regenerative Medicine was formed when voters in the state approved a 2004 ballot proposition providing $3 billion of taxpayer funding for stem cell experimentation.

A different proposal has been approved for trial in the United Kingdom.  It involves a strategy for avoiding a baby inheriting mitochondrial disease from the genes of its biological mother.  The strategy is to merge the nucleus of an egg from the affected mother with the egg of another woman who has no genetic anomaly and then have the merged egg fertilized by the sperm of a man.  This would produce a baby that genetically has three parents but does not develop mitochondrial disease.

The worldwide controversy surrounding this experimental procedure is that it would allow the baby to pass on its altered genetic code to its eventual offspring.  This means the change created by the merged eggs constitutes genetic germline modification.

Marcy Darnovsky, executive director of the Center for Genetics and Society in Berkeley, California, in a July 17, 2013 issue of Nature magazine states “Were the United Kingdom to grant a regulatory (permanent) go-ahead, it would unilaterally cross a legal and ethical line on this issue that has been observed by the entire international community.  This consensus holds that genetic-engineering tools may be applied, with appropriate care and safeguards, to treat an individual’s medical condition, but should not be used to modify gametes or early embryos and so manipulate the characteristics of future children.”

In both of these cases the specifics, especially given the targeted outcomes, clearly offer benefit, if successful, for thousands of people.  Issues arise however, when what happens in the experiments is generalized to permit a host of other experiments with far less compelling outcomes or even risks of serious harm.

These experiments should cause each of us to personally consider what kind of genetic engineering should be allowed.  A series of questions come to mind.  For instance, should the applied science of genetic engineering continue to be largely unregulated?  Should exceptions be made and by whom?  Whom should we appoint to sit in judgment and make decisions for us?  How will those we appoint represent us faithfully and how will they know what we collectively think?  These scientific issues may have a profound effect on our collective future.  They deserve our personal attention.

Use the following links to obtain additional information or see original source documents:

http://www.sciencemag.org/content/340/6140/1509.sumary?sid=ad66cb5e-78e1-449d-936b-79d2d5e8e5a1

http://news.sciencemag.org/health/2013/03/u.k.-agency-cautiously-endorses-mitochondria-replacement

http://www.nature.com/news/a-slippery-slope-to-human-germline-modification-1.13358

http://www.the-scientist.com/?articles.view/articleno/34790/title/uk-may-allow-mitochondrial-replacement

http://www.guardian.co.uk/science/2012/jan/05/chimera-monkeys-combining-several-embryo

Comments (0)

Advertise Here
Advertise Here
February 2018
S M T W T F S
« Feb    
 123
45678910
11121314151617
18192021222324
25262728