Changes in the Organization of Tubulin during Meiosis in the Eggs of the Surf Clam, Spisula Solidissima

Effect of taxol on first and second meiotic spindle formation in oocytes of the surf clam, Spisula solidissima.

The effect of taxol on first and second meiotic spindle formation was examined in oocytes of the surf clam, Spisula solidissima, by immunofluorescence staining with anti-tubulin antibody. The first meiotic spindle appeared to form as in untreated control cells. However, the spindle did not migrate toward the periphery of taxol-activated oocytes, resulting in blockage of the formation of the fir...

Purification and characterization of oocyte cytoplasmic tubulin and meiotic spindle tubulin of the surf clam Spisula solidissima

Assembly-competent tubulin was purified from the cytoplasm of unfertilized and parthogenetically activated oocytes, and from isolated meiotic spindles of the surf clam, Spisula solidissima. At 22 degrees C or 37 degrees C, Spisula tubulin assembled into 48-51-nm macrotubules during the first cycle of polymerization and 25-nm microtubules during the third and subsequent cycles of assembly. Macro...

Evidence for a non-tubulin spindle matrix and for spindle components immunologically related to tektin filaments.

Tektins were originally described as a set of three filamentous proteins (tektin A, B and C) associated with the walls of axonemal microtubules of sea urchin sperm. Using affinity-purified polyclonal antibodies raised against tektins of two sea urchin species, Lytechinus pictus and Strongylocentrotus purpuratus, we looked for tektin-like components in microtubule systems other than axonemes. By...

Isolation of Spindles from the Surf Clam Spisula Solidissima

Oocyte activation and passage through the metaphase/anaphase transition of the meiotic cell cycle is blocked in clams by inhibitors of HMG-CoA reductase activity

Cell cycle progression for postembryonic cells requires the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-R), the enzyme which catalyzes the production of the isoprenoid precursor, mevalonate. In this study, we examine the requirements of HMG-R activity for cell cycle progression during the meiotic and early mitotic divisions using oocytes and dividing embryos from the surf c...