Suppression of polar body formation by cytochalasin B and fusion of the resulting plural female pronuclei in eggs of the starfish, Asterina pectinifera.

In the starfish Asterina pectinifera, treatment of the eggs with cytochalasin B inhibits formation of the first or second polar body depending on when cytochalasin B is applied. Consequently, plural female nuclei are produced within the egg. These plural nuclei can fuse with each other after the egg is artificially activated with thymol. The further development of the eggs proceeds normally at least to the early blastula stage.