Hypotonic buffer induces meiosis and formation of anucleate cytoplasmic islands in the egg of the two-spotted cricket Gryllus bimaculatus
Article first published online: 6 MAY 2003
Development, Growth & Differentiation
Volume 45, Issue 2, pages 103–112, April 2003
How to Cite
Sarashina, I., Shinmyo, Y., Hirose, A., Miyawaki, K., Mito, T., Ohuchi, H., Horio, T. and Noji, S. (2003), Hypotonic buffer induces meiosis and formation of anucleate cytoplasmic islands in the egg of the two-spotted cricket Gryllus bimaculatus. Development, Growth & Differentiation, 45: 103–112. doi: 10.1034/j.1600-0854.2004.00679.x
- Issue published online: 6 MAY 2003
- Article first published online: 6 MAY 2003
- Received 17 September 2002; revised 8 October 2002; accepted 27 December 2002.
- egg activation;
- Gryllus bimaculatus;
- hypotonic buffer
In insects, egg activation is known to occur in vivo and independently of fertilization, but its mechanisms are poorly understood. To gain understanding of these mechanisms, an attempt was made to activate the egg of Gryllus bimaculatus in vitro. It was found that meiosis resumed and was completed in unfertilized eggs treated with hypotonic buffer. Early developmental processes in activated, unfertilized eggs were investigated and compared with those in fertilized eggs. Mitosis did not progress, resulting in formation of anucleate cytoplasmic islands (pseudoenergids). Development in the activated, unfertilized eggs stopped at this stage and both yolk subdivision and cellularization did not occur. To elucidate the role of the nucleus in the developmental process to the syncytial stage in fertilized eggs, eggs were treated with aphidicolin to inhibit DNA polymerization. It was found that pseudoenergids also formed in these aphidicolin-treated fertilized eggs. These results demonstrate that pseudoenergids can increase in number independently of nuclei, suggesting that the cytoplasm rather than the nucleus plays the primary role in development to the syncytial stage in G. bimaculatus.