Abstract
Centriolar complexes isolated from sperm of the starfish, Asterina pectinifera, could initiate irregular cleavage by injecting them into the fertilized eggs of the sand dollar, Scaphechinus mirabilis. Unfertilized sand dollar eggs could be activated when Ca2+ concentration in the egg cytoplasm increased by means of microinjecting calcium buffers in which the concentration of free Ca2+ was controlled by mixing calcium salt and calcium chelator at various proportions. When the centriolar complexes were injected into Ca2+-activated eggs, aster formation was induced in 25 out of the 55 eggs injected with calcium buffers at an intracellular Ca2+ level above 2.9 μM. The number of asters detected in one egg was quite variable, ranging from 2 to 20. The pronucleus in injected eggs was seen to migrate towards the induced asters. Eight of those 25 eggs cleaved.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 450-454 |
| Number of pages | 5 |
| Journal | Experimental Cell Research |
| Volume | 141 |
| Issue number | 2 |
| DOIs | |
| State | Published - Oct 1982 |
Bibliographical note
Funding Information:Fig. 3. Irregular cleavage of an unfertilized egg in which many asters were formed by microinjection. (a-c) were taken at 97, 101 and 108 min, respectively, after microinjection of both Ca-HEDTA buffer at a ratio of 3 (120 PM Ca’+) and centriolar complexes. In We express our gratitude to Professor Y. Hiramoto for his valuable advice and kind criticism in preparing the manuscript. Thanks are also due to Professors H. Kanatani and H. Sakai for their kind suggestions. We wish to thank the staff of Asamushi Marine Biological Station and Ushimado Marine Biological Station for supplying the starfish and sand dollars, respectively. This work was supported by grants-in-aid for scientific research from the Jaoan Ministrv of Education, Science and Culture to’Dr Y. Hi&mot0 (No. 548015). to Y. H. (No. 474331) and postdoctral fellowship to R. K.