Generation of asymmetry and segregation of germ-line granules in early C. elegans embryos.
Germ-line granules in C. elegans embryos (P granules) can be visualized by immunofluorescence microscopy using a monoclonal antibody. In mutant zygotes with abnormal spindle orientations and in wild-type zygotes treated with the microtubule inhibitors nocodazole, colcemid, vinblastine, and griseofulvin, both P-granule segregation to the posterior pole and the concomitant pseudocleavage occur apparently normally, but the normally concurrent migration of the pronuclei is inhibited. Conversely, treatment of wild-type embryos with the microfilament inhibitors cytochalasins D and B inhibits P-granule segregation and pseudocleavage, as well as other manifestations of polarity, without preventing pronuclear migration. The results suggest that P-granule segregation does not require either the spindle or cytoplasmic microtubules, but that this process as well as generation of other asymmetries does require cytoskeletal functions that depend on microfilaments.
D000818:Animals; D000911:Antibodies, Monoclonal; D002107:Caenorhabditis / Q000502:physiology*; D002467:Cell Nucleus / Q000502:physiology; D003594:Cytoplasmic Granules / Q000276:immunology / Q000502:physiology*; D003599:Cytoskeleton / Q000502:physiology*; D005260:Female; D008870:Microtubules / Q000502:physiology; D008938:Mitosis; D009068:Movement; D008941:Spindle Apparatus / Q000502:physiology; D015053:Zygote / Q000502:physiology* / Q000648:ultrastructure
D000911:Antibodies, Monoclonal