Martin H. Johnson

Mosaicism in organisation concanavalin A receptors on surface membrane of mouse egg

PLANT lectins have proved to be useful probes of the surface properties of a variety of cells and membranes, providing data on the relative mobility of intramembranous macro-molecules in different conditions1 and on the organisation of oligosaccharides on the cell surface. We report here the use of fluorescent concanavalin A (con A) as a probe to analyse the surface properties of the unfertilised and fertilised mouse egg. Similar experiments were carried out independently at both Cambridge and Birmingham and the results are combined.

Legal confusion over 'cloning' risks throwing baby out with bathwater.

Sir — The UK Chief Medical Officer has supported the recommendation that the 1990 Human Fertilisation and Embryology (HFE) Act should be amended to allow therapeutic cloning of humans, for research purposes only. He also recommends: “The transfer of an embryo created by cell nuclear replacement into the uterus of a woman (so-called ‘reproductive cloning’) should remain a criminal offence” (recommendation 7 in ref. 3). This recommendation implies that cell nuclear replacement and cloning are one and the same. They are not. If the recommendation is accepted as it stands, it risks perpetuating a confusion in UK law — already found in the HFE Act: section 3 (3) (d) — and possibly thereby influencing laws elsewhere. If so, this might reduce the future treatment possibilities for some infertile couples. Nuclear transfer constitutes reproductive cloning only when the individual so created is genetically identical to the nuclear donor. However, it is theoretically possible to use the nuclear transfer technique to generate a genetically biparental child. For couples in which one or both completely lack any germ cells or the means of producing them, the only current treatment option is gamete or embryo donation. However, one or both parents then lack a genetic contribution to their offspring. In the future, such couples may be able to overcome this problem by use of a nuclear transfer approach in which haploid nuclei are generated from parental diploid somatic cells and not via gametes. Two types of approach might be used to achieve this outcome. In the first approach, a somatic cell from one parent or from each parent would be induced in vitro to undergo meiotic reduction to produce two haploid cells, nuclei from which would then be used as donors for transfer to a recipient oocyte. A second approach would be to generate a tetraploid egg by transfer of one diploid somatic nucleus from each parent to an enucleated preanaphase I oocyte capable of undergoing a reduction division and then subsequent activation, so as to establish diploidy. Although several biological and technical problems must be solved before these approaches are available and safe, such therapy does not seem beyond the realm of eventual possibility. However, both these approaches use nuclear transfer and so would be prohibited under UK law. We draw attention to these possibilities now, both to encourage discussion of their social desirability and ethical status, and to stimulate a more accurate and informed use of language in science, politics and law. If legislation is being proposed, it must say what it means. If the legal intention is to prohibit production of an individual who is genetically identical or almost identical to another individual, then the law should use words that attain this objective, and this only. If it does not do so, potentially beneficial applications of nuclear transfer technology for human reproductive purposes may in future be prohibited accidentally. Martin H. Johnson*, Jacek Z. Kubiak† *Department of Anatomy, Downing Street, Cambridge CB2 3DY, UK †Department of Biology and Genetics of Development, UPR 41 CNRS, University of Rennes 1, Faculty of Medicine, 2 avenue du Professeur Léon Bernard, CS 34317, 35043 Rennes cedex, France

A Scientist in the World of Art

Aesthetics and the GestaltA Collection of Essays and Other Writings. By Ian Rawlins. Pp. xi + 228 + 10 plates. (Edinburgh and London: Thomas Nelson and Sons, Ltd., 1953.) 18s. net.