Gene Action Changes during Early Embryogenesis

  • Lawrence S. Dillon


The early events in the development of the fertilized egg into an embryo involve little or no growth but simply successive divisions (cleavages) into increasingly numerous, but even smaller, cells. Among metazoans, the first clusters, or plates, of cells thus produced are followed by more complexly organized series of stages, most of which are considered to be universal in occurrence in animals of all types, while in plants quite different stages are to be found. As customary, in the present section the most thoroughly explored aspects of the topic, embryogenesis in metazoans, is presented first, followed by the less thoroughly investigated ones to provide a full spectrum. While descriptions of embryonic stages necessarily occupy a large share of the pages, the changes in gene expressions observed in altered cell shape, behavior, and fates remain the major objective. Despite the abundance of evidence of the proteinaceous nature of those genie changes, only a relatively small proportion have been specifically identified.


Early Embryogenesis Cleavage Stage Neural Plate Primitive Streak Animal Pole 
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Copyright information

© Springer Science+Business Media New York 1983

Authors and Affiliations

  • Lawrence S. Dillon
    • 1
  1. 1.Texas A & M UniversityCollege StationUSA

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