Centriole size modifications during the cell cycle of the amoebae of the myxomycetePhysarum polycephalum

Anterior and posterior centrioles ofPhysarum amoebae are indistinguishable by their size during interphase but there is a correlation between the size of the two centrioles in the same amoeba. The interphase length of centrioles in diploid amoebae possessing only one pair of centrioles was 11% longer than in the case of the haploid strain. Treatment with taxol led to a 23 and 32% increase of the mean length in interphase and blocked mitosis, respectively. Conversely, during control mitosis the parental centrioles showed a 12% decrease of their mean length while the size of the daughter centrioles increased progressively. Neither nocodazole nor cold treatment induce a decrease of centriole length. The mean length of the cartwheel structure (internal proximal part) although constant during mitosis could be increased 24% in the presence of taxol. Similarly there was a correlation between the number of anterior satellites and the centriole length.