Confocal microscopy and 3-D reconstruction of the cytoskeleton of Xenopus oocytes

Xenopus oocytes contain a complex cytoskeleton composed of three filament s ystems: (1) microtubules, composed of tubulin and at least three different microtubule-associated proteins (XMAPs); (2) microfilaments composed of act in and associated proteins; and (3) intermediate filaments, composed of ker atins. For the past several years, we have used confocal immunofluorescence microscopy to characterize the organization of the oocyte cytoskeleton thr oughout the course of oogenesis. Together with computer-assisted reconstruc tion of the oocyte in three dimensions, confocal microscopy gives an unprec edented view of the assembly and reorganization of the cytoskeleton during oocyte growth and differentiation. Results of these studies, combined with the effects of cytoskeletal inhibitors, suggest that organization of the cy toskeleton in Xenopus oocytes is dependent upon a hierarchy of interactions between microtubules, microfilaments, and keratin filaments. This article presents a gallery of confocal images and 3-D reconstructions depicting the assembly and organization of the oocyte cytoskeleton during stages 0-VI of oogenesis, a discussion of the mechanisms that might regulate cytoskeletal organization during oogenesis, and speculates on the potential roles of th e oocyte cytoskeleton during oogenesis and axis formation (C) 1999 Wiley-Li ss, Inc.