In order for you to get the most out of the debate, the student presenters have asked that you think about these issues tonight, and come with questions about the cloning debate.† These can be scientific, ethical, legal, or political questions, and the panelists hope that you will bring up topics you have read about in the newspapers or heard on tv.†
4/8/03 The Boston Globe: Cloned oxen give hope to conservationists: Two calves from endangered species born on Iowa farm
4/10/03 National Public Radio: Cloning primates proves to be a seemingly impossible task
4/17/03 The New York Times: Stem Cells May Repair Damage from Multiple Sclerosis
4/22/03† The Washington Post: Stem Cell Strides Test Bush Policy; Scientists Push for Use Of Newer Cell Colonies
4/21/03 The Times (London): Clones surprise scientists by being different
4/23/03 †The Vancouver Sun: Baby teeth contain stem cells: Researchers find totsí tooth cells might be used instead of cells from embryos
††††††††††† One source of confusion in the national debate is the way different terms are defined.† To be clear, the following definitions are presented:
††††††††††† In mammalian development, the early embryo forms a blastocyst, consisting of an outer cell layer (the trophoblast) and an inner cell mass (ICM). It is the cells of the ICM that will form all of the tissues of the resulting individual.† Isolated ICM cells are called embryonic stem cells because they are unspecialized, can be grown in culture, and can differentiate into a wide variety of cell types (pluripotent).†
††††††††††† Somatic cell nuclear transfer: this is the technical term for what is commonly known as cloning.† In this process the nucleus from a single body cell (skin, liver, etc.) is put into an egg whose own nucleus has been removed.† The inserted nucleus is reprogrammed to direct the entire repertoire of development, and an organism is formed who has the genetic identity of the nucleus donor.† Reproductive cloning: The use of somatic cell nuclear transfer to create an embryo to be implanted into a uterus, with the express desire of creating a new organism.† Therapeutic or research cloning: The use of somatic cell nuclear transfer to create a blastocyst from which embryonic stem cells will be isolated.† These stem cells will have the genetic identity of the nucleus donor.† The field of regenerative medicine is based on the possibility of using such cells to repair damaged/diseased tissues.† The therapeutic cloning part comes in to avoid immune rejection of the new stem-cell derived tissues when given to a patient.†
††††††††††† Many tissues have recently been shown to have populations of cells that are relatively unspecialized, and that can differentiate into other cell types.† These are called adult stem cells, and the most well-studied are the hematopoietic stem cells from bone marrow, used to treat certain types of leukemias.†
Two excellent books from the National Academies of Science Press are available free online:
Scientific & Medical Aspects of Human Reproductive Cloning (2002): www.nap.edu/books/0309076374/html/
Stem Cells and the Future of Regenerative Medicine (2002): http://www.nap.edu/catalog/10195.html
††††††††††† The current laws in the United States dealing with cloning and stem cell research are quite confusing, and are apt to change in the near future.† On the national level, President Bush has called for a complete ban on both reproductive and therapeutic cloning.† The House of Representatives passed such a ban last month (March, 2003), and the Senate is expected to vote on a similar bill soon.† This would criminalize all research on human somatic cell nuclear transfer.† In August of 2001 President Bush made a speech saying that federally funded research on human embryonic stem cells could only be conducted on the approximately 70 cell lines already in existence. In January, 2002, President Bush named the members of his new Council on Bioethics, charged with educating the public, and advising the President, on issues of national concern in the fields of biomedicine. The transcripts of the meetings of the Council are available on the website www.bioethics.gov.† A book describing their deliberations and findings on human cloning and embryonic stem cells, called Human Cloning and Human Dignity: An Ethical Inquiry, is available free online at www.bioethics.gov/reports/cloningreport/index.html.† The council recommended a ban on reproductive cloning, and a four-year moratorium on therapeutic cloning research.
Remember--the views expressed by the student panel members are NOT their own personal views.† They are the views of the expert they represent.
PLEASE BE ON TIME FOR CLASS ON TUESDAY.
WE WILL BEGIN THE PANEL PROMPTLY!