EN
The purpose of this paper is to review information regardind the co-ordination of nuclear and cytoplasmic events during embryo reconstruction, in particular the direct and indirect effects of maturation (meiosis) mitosis promoting factor (MPF), upon the transferred nucleus.These will be discussed in relation to DNA replication, the maintenance of correct ploidy, the occurence is primarilu concerned with the reconstruction of mammalian embryos, specific examples from amphibians will also be cited.