The ethics of reproductive cloning.

I. INTRODUCTION Reproductive cloning is unethical in its current technological stage. Understanding the important genetic and biological differences between an embryo produced by natural or assisted reproduction methods--such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI)--versus an embryo produced by reproductive cloning is essential in arriving at this position. A number of biological processes, necessary for the development of a healthy individual and the maintenance of a robust gene pool, are bypassed by the reproductive cloning process. From a medical ethics perspective, bypassing these processes subjects the cloned individual (and its future generations) to unacceptable levels of risk. From a societal perspective, the virtue of the ends of reproductive cloning must be considered in light of biological urges, the influence of laws, and societal mores. The ethical concerns of reproductive cloning received substantial attention following the cloning of Dolly the sheep in 1997, and were revived by recent Clonaid's recent claim that it had successfully cloned a human. (1) Even though there has been considerable sensationalism and hype surrounding these reports, the popular press must be credited for at least attempting to educate the general public on the underlying science of cloning technology, especially regarding the differences between therapeutic cloning and reproductive cloning. (2) To be clear on terminology, the following discussion uses the terms "ethics," "cloning," and "reproductive cloning" in following manner: * Ethics is a branch of philosophy dealing with what is good and bad and with moral duty and obligation. (3) It is a system of moral principles. (4) The argument presented below addresses both the medical ethics and broader societal ethics of reproductive cloning. * Cloning is a term describing a process of producing copies of a cell, tissue, or organism from a single cell by mitosis, the asexually producing progeny of an individual. (5) In the research laboratory, cloning is frequently used to generate large quantities of genetic material for a wide variety of experimental applications, including research to identify disease-causing genes. * Reproductive cloning is the process by which an embryo is produced through the removal and transfer of nuclear material in a cell, and the use of a growth medium to manipulate that cell into undergoing mitosis. (6) This process is the culmination of advancements in recombinant DNA technology and IVF methods. (7) Reproductive cloning has been successfully employed in the lab to produce tadpoles, (8) frogs, (9) mice, (10) cows, (11) and sheep. (12) For a number of fundamental biological reasons, reproductive cloning does not produce an identical copy of an individual. Genetically, reproductive cloning differs from procreation in that the nuclear genomes of two individuals are not combined in the same way; genetic recombination during this process occurs in a manner that does not result in a genetically unique individual. This technical and biological difference makes reproductive cloning significantly different than assisted reproduction methods, e.g., IVF and ICSI, even though both procedures require substantial human intervention. II. A BRIEF HISTORY OF REPRODUCTIVE CLONING The history of the laboratory work leading to the reproductive cloning of mammals has been well-documented. (13) Briefly, in the 1960's John Gurdon combined an egg cell (complete with cytoplasm) from which the nucleus had been removed, with the nucleus of an intestine cell to clone frogs. (14) Donor-cytoplasmic material was not transferred however, and the resulting tadpoles did not survive to maturity. (15) Fifteen years later, Solter and McGrath performed nuclear transfer to produce the first cloned mouse. (16) They changed Gurdon's method by fusing a mouse zygote acceptor cell, whose cytoplasm remained intact but from which the nucleus had been removed, with the donor nucleus from a genetically distinct mouse embryo. …