On the Mechanism of Ooplasmic Segregation upon Fertilization in Oryzias latipes

Abstract

Pulsating contraction of peripheral ooplasm of the eggs of a cyprinodontoid fish, Oryzias latipes, was observed after alveolar breakdown upon fertilization.The contraction is initiated at the animal pole region in the vicinity of the fertilization cone and propagates toward the vegetal pole.The movement of ooplasmic inclusions and of carbon particles injected into the peripheral ooplasm was examined after insemination, and it was suggested that ooplasmic segregation is induced by contractions of the peripheral ooplasm.