ThreeDimensional imaging of fertilization and early development

The field of biological microscopy has recently enjoyed major technical advances, exemplified by the development of fieldemission lowvoltage scanning electron microscopes and laser scanning confocal light microscopes. In addition, computer processing of microscopical data is revolutionizing the way morphological information is imaged. In this paper, we illustrate methods by which this new technology can be used to examine events in fertilization and early development in three dimensions. Different types of specimen preparation protocols, using both echinoderm and mammalian gametes and embryos, are evaluated for their ability to preserve accurately the threedimensional organization of these specimens for imaging by both lowvoltage scanning electron microscopy and laser scanning confocal light microscopy. Copyright1991 WileyLiss, Inc.