Overview
Reproductive Cloning
Research Cloning
Policy Overview
Conclusion

Cloning Overview: The Science

Cloning is the asexual production of a genetically identical copy. The term cloning is sometimes used to refer to a process called somatic cell nuclear transfer (SCNT), in which a somatic (body) cell is combined with an enucleated egg (an egg from which the nucleus – containing the cell's DNA – has been removed) to create an embryo. The resulting embryo can either 1) be implanted in a woman's uterus to develop into a human being in what is commonly called "reproductive" cloning; or 2) be used to extract stem cells for research purposes in what is commonly called "therapeutic" or "research" cloning.

Reproductive Cloning

Reproductive cloning occurs when a zygote created through SCNT develops into an embryo and is implanted in a woman’s uterus. The resulting child is genetically identical to a single parent.

So far scientists have not successfully cloned a human being, but have cloned some types of animals. According to a 2002 report from the National Academies of Science, cloning in mammals using nuclei from adult or fetal animal cells has been successful in sheep, mice, pigs, goats and cattle. However, high incidences of miscarriage, abnormalities, and neo-natal death are reported even among successful cases of animal cloning.

Research Cloning

Research cloning, also called therapeutic cloning, can be used to create embryonic stem cells. When a fertilized egg divides and multiplies, it becomes a blastocyst, or a core of embryonic stem cells surrounded by a protective wall. These stem cells can be removed and placed in cultures. Cell differentiation occurs as the stem cells begin to develop into every type of cell in the body. These cells can then be used to replace dead or diseased cells and tissue.

In therapeutic cloning, a somatic cell is combined with an enucleated egg, which divides and eventually becomes a blastocyst from which stem cells can be extracted (subsequently destroying the embryo). The benefit of using stem cells created through SCNT is that the new cells would contain the same genetic material as the patient, eliminating the risk that the patient’s body will reject them. In addition, many scientists argue that research using SCNT will lead to a better understanding of cell development and mutations, and the evolution of disease.

It is important to note that alternate sources of stem cells exist – embryonic stem cells can be derived from left over embryos created for in vitro fertilization procedures. In addition, non-embryonic, or adult stem cells, can also be used for research towards medical treatments, but studies have shown that adult stem cells may not be as pluripotent (versatile) as embryonic stem cells. In both cases, however, medical applications using such stem cells would need to include means to overcome immune rejection in patients.

Policy Overview

The public debate over cloning began with the creation of Dolly the sheep in 1997, and has recently been re-ignited by scientific advancements in SCNT, including the announcement by Advanced Cell Technology Inc. that is had successfully cloned human embryos. Presently, most policymakers agree that human reproductive cloning should be banned. The point of contention is the regulation of research involving SCNT, which many proponents believe has the potential to lead to treatments, and even cures, for diseases such as diabetes, Parkinson's and Alzheimer's.

Many opponents of cloning for research purposes cite health and safety concerns (for both the prospective patients and the women who donate their eggs). Others are opposed to the creation of "life" for the purpose of destroying it. Still others oppose research cloning on the grounds that it may eventually lead to irreversible alterations of the gene pool. Most cloning opponents argue that embryo cloning for research purposes will likely lead to reproductive cloning or to the genetic alteration of the species (the "slippery slope"), and anything other than a comprehensive ban on SCNT would be impossible to enforce. Others argue that if effective prohibitions on reproductive cloning are put in place, research cloning should be allowed, though with oversight mechanisms to prevent abuse.

Proposed federal anti-cloning legislation ranges from explicit support for research cloning to a permanent ban on SCNT, including criminal penalties. Some environmental and other non-governmental organizations have proposed a temporary moratorium on both research and reproductive cloning, although to date this alternative is not embodied in any legislation.

Conclusion

RHTP believes that SCNT for research purposes holds great potential for improving the health and wellbeing of the public and supports the allocation of resources to the further development and implementation of this research. We also unequivocally support the need for strong regulatory guidelines to ensure the safety and efficacy of this research. Such guidelines include but are not limited to:

• Ensuring informed consent and confidentiality of all participants.
  
• The availability of short and long term safety and efficacy data on SCNT for public review.
  
• The development of mechanisms which prevent the use embryos created for SCNT, for reproductive purposes.
  
• The establishment and enforcement of civil penalties for those who undertake unethical practices.