Elongation factor 1α is a component of the subcortical actin bundles of characean algae.

Antibodies to elongation factor 1α (EF1α), a known 50 kDa actin-bundling protein in Dictyostelium, identified a protein in a whole cell extract of the characean alga Nitella pseudoflabellata that had an apparent molecular weight of 51 kDa. Indirect immunofluorescence microscopy revealed labelling by the EF1α antibodies of the subcortical actin bundles, even after the motile organelles of the endoplasm were removed by perfusion with ATP-containing solutions.     

Microtubule organization differs between acid and alkaline bands in internodal cells ofChara but bands can develop in the absence of microtubules

We have studied the relationship between pH banding and the organization of cortical microtubules in the alga Chara corallina Klein ex Willd. Microtubules were visualized by immunofluorescence and also by imunogold-silver enhancement to allow immediate comparison of microtubule arrangement with visible structural cell features. In cells that are nearing growth completion, microtubule number and alignment change between acidic and alkaline bands over a distance of a few micrometres. Thus, it appears that the still unknown mechanisms for microtubule organization respond to the localized differences in membrane properties. Band formation was not prevented when microtubules were depolymerized with the herbicide oryzalin, demonstrating that microtubules are not necessary for pH bands to develop in these cells.Abbreviations DMSO dimethylsulfoxide - MT microtubule We thank Frank Gubler for helpful advice on immunogold-silver enhancement procedures, Brian Gunning for tuition in confocal microscopy, Ann Cork for assistance with photography and Dean Price for helpful discussions. G.O.W. gratefully acknowledges the receipt of a National Research Fellowship and a Queen Elizabeth II Fellowship from the Australian Research Council.