Mitosis in the protostelidCeratiomyxella tahitiensis(Eumycetozoa)

摘要

Mitosis is dimorphic in the protostelidCeratiomyxella tahitiensis. The spindle in the amoebo-flagellate state of the life cycle is open and centric; the microtubular rootlet system which surrounds the centrioles during interphase breaks down during mitosis. The spindle in the plasmodial state is open and acentric. The spindle develops outside the nuclear envelope during prophase and drops into the nucleus during prometaphase when the nuclear envelope breaks down. A polar microtubular organizing center appears at metaphase and lasts through telophase. Amoebo-flagellate mitosis is similar to that found in the amoebo-flagellates of other Eumycetozoa. Plasmodial mitosis is unique among the eumycetozoans. This provides support for the hypothesis that the flagellate Eumycetozoa are derived from a common flagellate ancestor and that certain groups of eumycetozoans have independently evolved unique, obligately amoeboid states.