Ultrastructure of egg activation and cortical reaction in the noble crayfish Astacus astacus.

摘要: Abstract Morphological changes in the gamete of female noble crayfish at four developmental stages were studied. Mature ovarian oocytes are enclosed by first envelope that consists two layers. Numerous pores visible on surface outer layer this and inner contains bottlebrush-shaped objects. Three types vesicles, including some highly moderately electron-dense multi-layered, occur cortex oocyte. In freshly ovulated eggs, closed, objects replaced a spongiform electron-lucent matrix containing scattered vesicles. One hour post-spawning, envelope, especially its layer, is condensed. The dense vesicles discharge their contents into perivitelline space, where they combine form second around egg. Twenty-four hours post-ovulation, space part egg cortex. continue to release further construction after 24 h post-spawning. attachment stalk derived from envelope. fertilization coat envelopes produced ovary cortical reaction, respectively.