Regulating the creation of novel beings.

• Author: Robert, Jason Scott
• Position: Canada

Introduction (1)

Bill C-l3, An Act respecting assisted human reproduction, (2) proposes to regulate various elements of the creation of novel beings. Though the bill is directed primarily at the techniques and processes of human infertility intervention, it is concerned secondarily with some aspects of human embryo experimentation. The bill thus deals with the circumstances under which chimera- and hybrid-making would and would not be permitted, where the hybrid or chimera is created in part from human biological materials.

In this brief commentary, I focus on the proposed regulation of chimera- and hybrid-making. I probe some definitional oddities in the relevant portion the bill, assess possible scientific rationales for creating transgenic beings from human genes and cells, and touch on ethical and legal aspects of regulating the creation of these sorts of novel beings.

1. Definitional Issues

   Bill C-13 distinguishes between "chimeras" and "hybrids." Creating either type of creature is, prima facie, prohibited under the bill, carrying a maximum penalty of a fine of $500,000 and/or a prison term of 10 years (though the actual penalty assessed may be less severe). Section 3 of Bill C-13 defines "chimera" as:

   1. an embryo into which a cell of any non-human life form has been introduced; or

   2. an embryo that consists of cells of more than one embryo, foetus or human being."

   "Embryo", as defined in s. 3, refers exclusively to human embryos:

   "embryo" means a human organism during the first 56 days of its development following fertilization or creation, excluding any time during which its development is suspended, and includes any cell derived from such an organism that is used for the purpose of creating a human being.

   "Hybrid" is also defined in s. 3 and means:

   (a) a human ovum that has been fertilized by a sperm of a non-human life form;

   (b) an ovum of a non-human life form that has been fertilized by a human sperm;

   (c) a human ovum into which the nucleus of a cell of a non-human life form has been introduced;

   (d) an ovum of a non-human life form into which the nucleus of a human cell has been introduced; or

   (e) a human ovum or an ovum of a non-human life form that otherwise contains haploid sets of chromosomes from both a human being and a nonhuman life form.

   Section 5(1)(i) prohibits chimera-making:

   5(1) No person shall knowingly

   (i)create a chimera, or transplant a chimera into either a human being or a non-human life form;

   Section 5(1)(j) prohibits hybrid-making:

   5(1) No person shall knowingly

   (j)create a hybrid for the purpose of reproduction, or transplant a hybrid into either a human being or a non-human life form.

   Are these definitions scientifically or legally adequate? Let us begin with hybrids. A vague definition of "hybrid" would not have sufficed, either legally or scientifically. An example of a vague definition is that provided by Genome Canada, and adopted from the Human Genome Project Information website: "The offspring of genetically different parents." (3) At least in the case of animals (including humans), unless the parents are identical twins, they will be "genetically different." A regulation prohibiting the creation of hybrids so defined would prohibit reproduction except--per impossibile--between identical twins!

   Within the context of a bill concerning human reproduction and human reproductive materials, a scientifically adequate definition of "hybrid" (involving human genetic or cellular material) should capture at least the following possibilities: the fertilization of a human ovum with non-human sperm; the fertilization of a non-human ovum with human sperm; the insertion of a non-human cell nucleus into a human enucleated ovum; and the insertion of a human cell nucleus into a non-human enucleated ovum. As written, the Bill C-13 definition of "hybrid" does indeed capture these four possibilities--subsections (a)-(d) in the definition cited above. The Bill C-13 definition is, however, more exhaustive, in that it contains as well a "catch-all" subsection--subsection (e): "a human ovum or an ovum of a non-human life form that otherwise contains haploid sets of chromosomes from both a human being and a non-human life form" (emphasis added). This fifth subsection captures possibilities for hybridizing human and non-human genomes not otherwise enumerated in the definition. Because the definition of "hybrid" employed in Bill C-13 is clear and exhaustive, the bill's prohibition on hybrid-making is thus very strong.

   The same is not true, though, of the prohibition on chimera-making. For regulatory purposes at least appropriately defining "chimeras" is considerably more complex than appropriately defining "hybrids." As noted above, the Bill C-13 definition of "chimera" captures two possibilities: the insertion of non-human cells into human embryos, and the inclusion, within any single human embryo, of cells from other human embryos, human foetuses, or human beings. It is prohibited either to create such chimeras, or to implant them in humans or non-humans. This is a narrow definition of "chimera"; the narrowness of the definition provides for both potential advantages and potential disadvantages.

   Among its potential advantages is its precision. A prohibition on the creation or implantation of chimeras so defined is clear: it is forbidden to knowingly add "foreign" cells to a human embryo by, for instance, fusing embryos, or to implant an embryo so manipulated.

   A second potential advantage is that the definition does not include, for instance, organ recipients (through either conventional or xenotransplantation) as chimeras. This is because the definition is restricted to the embryonic stage of human development. Other definitions of "chimera" are much more inclusive, and would require deeming...