Institute of Genetic Homeostasis, Tihoretsky prospect 4, St.- Petersburg 194064, Russia

Abstract

The author suggests the scheme of gene regulation including temporal and spatial ones that can be applied to the embryogenesis of invertebrates with highly deterministic cell destiny. Two main mechanisms are responsible for the development: 1) The change of cytoplasmatic determinants that occurs simultaneously with cytoplasmatic cycles. The latter ones normally coincide with mitosis cycles; 2) Binary segregation of these determinants at every mitosis. The change of determinants can take place as a result of stage by stage switching of transcription accompanied by degradation. Synchronism of these switchings with mitosis cycles can be provided by the 'windows' of transcription during every cycle. This mechanism of embryogenesis does nor require any restructuring of gene material for calculation of cell division. This scheme coincides with experimental investigation of embryogenesis of animals with mosaic development type. As an example the author presents the scheme of closed development cycle of "one-dimensional organism" and its genome. For such "organism" the scheme provides precise prediction and automatism of development and its reproduction in different generation.