Int. J. Dev. Biol. 48: 607-612 (2004)

© UBC Press
Essay

Key words: nuclear transfer, cloning, Delage, Spemann

Yves Delage (1854-1920) as a forerunner of modern nuclear transfer experiments

JEAN-CLAUDE BEETSCHEN*^,1 and JEAN-LOUIS FISCHER^#,2

¹Centre de Biologie du Développement, Université Paul-Sabatier, Toulouse, France and ²Centre Alexandre Koyré, Museum National d'Histoire Naturelle, Paris, France

*Request reprints from: beetsche@cict.fr

ABSTRACT  It is generally considered that animal cloning by nuclear transfer originated in proposals made by Hans Spemann (1936), following his experiments on delayed nucleation in the newt egg, which were preceded by similar attempts using the sea-urchin egg (Loeb, 1894). Briggs and King (1952) were the first to succeed in transplanting blastula and gastrula nuclei into the enucleated frog egg and in obtaining a significant number of normal tadpoles by means of this technique. We present evidence that much earlier (1895) Yves Delage (1854-1920), a French biologist, had clearly formulated the same experimental project of nuclear transfer, as a means to test Weismann's theory of cell differentiation during embryonic development. This was also Spemann's motivation. Both Delage and Spemann were aware of Loeb's experiments (1894), in which delayed nucleation in the sea-urchin egg was found to result in twin larvae. It is difficult to decide whether Delage's project was influenced by Loeb's findings. On the other hand, it seems that Spemann was not aware of Delage's proposal, since he did not express his own ideas on extended nuclear transfer before 1936. Finally, neither Delage nor Spemann imagined that nuclear transfer could be a means of obtaining groups of genetically identical animals (reproductive cloning).