Basal body loss during fungal zoospore encystment: evidence against centriole autonomy.

The controversial question of the possible autonomy of centrioles, as shown by the persistence of all or part of them in the generative cell line throughout the life cycle of organisms, remains unresolved. All previous reports on shedding or withdrawal of cilia and flagella showed that their basal bodies (= centrioles) were retained in the cells where they may, or may not, subsequently disassemble. We show that in the fungus Neocallimastix sp. the basal bodies are discarded with the flagella when zoospores encyst. This shedding of basal bodies argues against centriolar persistence in any form and thus against their autonomy and endosymbiotic origin.