DNA Content and Fragmentation of the Egg Nucleus of Trichoplax adhaerens

Abstract

Abstract Under culture conditions the egg nucleus of Trichoplax adhaerens reaches an unusually high and variable DNA content. Before the "fertilization membrane" is formed, the nucleus undergoes fragmentation. It is assumed that culture conditions differ from natural conditions by preventing the switch-over from the S-phase to the G 2-phase of the cell cycle: DNA replication continues and nuclear division is impossible. Cleavage ceases at an earlier or later stage.