Abstract
A transient sensitivity to cytochalasin B was detected in freshly fertilized sea urchin eggs. Large membrane-limited protrusions formed when cytochalasin B was added between 1 and 6 min postinsemination. When cytochalasin B was removed from the cultures, eggs continued to develop with protrusions remaining, and cleavage furrows formed through many of the protrusions. Electron microscopy showed that cytochalasin B disrupted the microfilamentous structures that formed in the egg cortex after fertilization. Protrusions also appeared when eggs were activated by the Ca2+ ionophore A23187 followed by cytochalasin B addition. Protrusions did not appear when cytochalasin B was added at any time prior to fertilization, during insemination, or after the 6-min period postinsemination. Mechanical compression or incubation in a cortical isolation medium were effective as treatments enhance the cytochalasin B-sensitive response. These results suggest a time frame for postfertilization changes in the cortex of the zygote.
Original language | English (US) |
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Pages (from-to) | 506-515 |
Number of pages | 10 |
Journal | Developmental Biology |
Volume | 80 |
Issue number | 2 |
DOIs | |
State | Published - Dec 1980 |
ASJC Scopus subject areas
- Molecular Biology
- Developmental Biology
- Cell Biology