The aim of this review is to compile, summarize and discuss the effects of microgravity on embryos, cell structure and function that have been demonstrated from data obtained during experiments performed in space or in altered gravity induced by clinostats. In cells and tissues cellular structure and genetic expression may be changed in microgravity and this has a variety of effects on embryogenesis which include death of the embryo, failure of neural tube closure, or final deformities to the overall morphology of the newborn or hatchling. Many species and protocols have been used for microgravity space experiments making it difficult to compare results. Experiments on the ways in which embryonic development and cell interactions occur in microgravity could also be performed. Experiments that have been done with cells in microgravity show changes in morphology, cytoskeleton and function. Changes in cytoskeleton have been noted and studies on microtubules in gravity have shown that they are gravity sensitive. Further study of basic chemical reactions that occur in cells should be done to shed some light on the underling processes leading to the changes that are observed in cells and embryos in microgravity.

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A robotic microscope was designed using a microcontroller with three stepper motors to control three-axis movement. Two 7 megapixel digital cameras controlled by the microcontroller capture images when the stage moves into position. Using 4 prisms, through focus time-lapse digital pictures of six views of Ambystoma mexicanum embryos (axolotl, a salamander) are taken every 5 minutes for 52 hours of early development, from fertilization to stage 20, i.e., neural tube closure. In-focus views [Gord83] of all sides of the embryo are calculated using several image fusion techniques. In the early embryo surface epithelial cells differentiate to form neural tissue and external skin tissue. Observing the whole embryo surface at cellular level will give a better idea of the stress and strain each cell undergoes and physical forces involved in cell differentiation, including waves of cell surface expansion or contraction Time-lapse photographs capture the dynamics of the embryo during development, that is lost in histological techniques that use non-living material.