Experimental Genetics of the Mammalian Embryo

Abstract

In recent years, several approaches suitable for the analysis of gene activity during mammalian embryogenesis have been realized in the mouse and I should like to briefly summarize these new results and discuss their relevance and applicability to experimental embryology. First, enucleation by removing either both pronuclei from the fertilized egg or the female pronucleus from the unfertilized egg provides an experimental means of analyzing the protein pattern derived from maternal mRNA stored during oogenesis. Secondly, microsurgical removal of one of the two pronuclei from the fertilized mouse egg makes it possible to study independently the maternal or paternal genome for its protein synthesis capacity during development. Thirdly, in nuclear transplantations the egg genome is replaced by a somatic cell nucleus in order to reveal the developmental potential of nuclei originating from different cell types and lineages at various stages of differentiation. Fourthly, in gene transplantations cloned recombinant DNA molecules are introduced into the developing organism via injection into the pronucleus of the fertilized egg to examine their presence, expression and regulation during mouse development.

This article is dedicated to the memory of Robert Briggs. It was first published in Partificiae Academiae Scientiarum Scripta Varia.