SYNTHESIS OF THE INNER CELL-WALL LAYER OF THE CHLAMYDOMONAD FLAGELLATE, GLOEOMONAS-KUPFFERI

An antibody to the inner wall layer of Gloeomonas kupfferi was isolate d and used in a developmental analysis of cell wall processing, secret ion and extracellular assembly. The focus of the processing of this ma trix layer is the endomembrane system, in particular the Golgi apparat us (GA) and contractile vacuole (CV). During interphase, inner wall ma terials are processed in the GA, packaged in trans face vesicles and t ransported to the CV, the final internal depository of wall precursors until release to the cell surface. During cell division, significant changes occur in the inner wall layer processing. Early on in cytokine sis, the GA does not label with our antibody, suggesting that other wa ll layers are being processed. In later stages of cytokinesis, the GA changes in morphology and begins to produce inner wall layer materials . These wall precursors are shuttled to the CV where they are released around the daughter cell protoplasts. The first wall layer that is fo rmed around daughter cells is the crystalline median wall layer. Once assembled, the inner wall layer condenses upon the crystalline layer a nd grows in size.