alpha-spectrin has a stage-specific asymmetrical localization during Xenopus oogenesis

Xenopus oocyte organization largely depends upon the cytoskeleton distribut ion, which is dynamically regulated during oogenesis. An actin-based cytosk eleton is present in the cortex starting from stage 1. At stages 4-6, a com plex and polarized cytoskeleton network forms in the cytoplasm. In this pap er, we studied the distribution of spectrin, a molecule that has binding si tes for several cytoskeletal proteins and is responsible for the determinat ion of regionalized membrane territories. The localization of alpha-spectri n mRNA was analyzed during Xenopus oogenesis by in situ hybridization on bo th whole mount and sections, utilizing a cDNA probe encoding a portion of X enopus alpha-spectrin. Furthermore, an antibody against mammalian alpha-spe ctrin was used to localize the protein. Our results showed a stage-dependen t mRNA localization and suggested that spectrin may participate in the form ation of specific domains in oocytes at stages 1 and 2 and 4-6. (C) 2000 Wi ley-Liss, Inc.