Development of surface pattern during division in Paramecium: III. Study of stomatogenesis in the wild type using antitubulin antibodies and confocal microscopy

Abstract

Summary Stomatogenesis, during the vegetative division of Paramecium, is a complex morphogenetic process involving massive proliferation of basal bodies and their progressive patterning to generate a new oral apparatus in the immediate vicinity of the old one. This new oral apparatus will be inherited by the posterior daughter cell while the old one remains in the anterior daughter cell. We have carried out a detailed description of the whole process, using new antibodies and confocal microscopy, allowing visualization of all basal bodies and a number of other cytoskeletal elements, thus completing our previous description of morphogenesis. The following inferences could be made: 1) The new oral structures are exclusively formed from the anarchic field by a two step wave of basal body duplication. These two steps strictly parallel, slightly in advance, those we have previously detailed at the level of the “somatic” cortex, suggesting *) that a common set of biochemical cascades is involved, **) that the OA may be triggering these cascades. 2) The initial proliferation of basal bodies occurs in the immediate vicinity of the parental “paroral kinety” which itself remains invariant and appears to dictate the progressive patterning of the oral anlage (as can be inferred from the staining intensity, distance and alignment of the basal bodies of the anarchic field with respect to the paroral kinety). This suggests that the concept of cytotaxis or structural guidance can be extended to the genesis of an elaborate set of basal bodies. 3) The number of basal bodies within the anarchic field is determined during this formation of the new oral apparatus. Thus, the size and possibly part of the pattern of the new OA is determined in one generation, with storage of morphogenetic potentialities used in the next generation. In this process, a slight cortical rotation around the cell axis is effected at each division. 4) The whole morphogenetic assemblage up to the level of the whole cell displays an overall left-right asymmetry which is progressively built up upon the basic asymmetry of the basal body.