title: Role of ooplasmic segregation in mammalian development.
abstract: A new micromanipulation technique permitted the scrambling of the zygote cytoplasm. Such interference had no effect on preimplantation development, and when zygotes with scrambled cytoplasm were transfered to the pseudopregnant females, normal and fertile mice were born. This demonstrates that no morphogenetic factors are prelocalized in the egg cytoplasm. Cleavage characteristics of mouse embryos provide the evidence that zygote cytoplasm does not define any determinate type of cleavage. We conclude that the mechanism of ooplasmic segregation is not used in the mouse (and presumably mammalian) development. It is suggested that the turning point in the evolution of mammalian embryogenesis was the transition to the intrauterine development, that started the process leading among other changes, to the loss of the ooplasmic morphogenetic determinants.
authors.affiliation: Department of Biochemical Genetics, Institute of Molecular Biology and Genetics, Academy of Sciences of the Ukraine, 252627, Kiev, Ukraine.
authors.forename: Sergei Vadimovich
authors.initials: SV
authors.lastname: Evsikov
authors.affiliation: Department of Biochemical Genetics, Institute of Molecular Biology and Genetics, Academy of Sciences of the Ukraine, 252627, Kiev, Ukraine.
authors.forename: Ludmila Michailovna
authors.initials: LM
authors.lastname: Morozova
authors.affiliation: Department of Biochemical Genetics, Institute of Molecular Biology and Genetics, Academy of Sciences of the Ukraine, 252627, Kiev, Ukraine.
authors.forename: Alexander Petrovich
authors.initials: AP
authors.lastname: Solomko
keywords: Cell differentiation; Cytoplasm; Evolution; Micromanipulation; Mouse embryo