Fig. 4. Immunolabeling with anti-ß-tubulin and anti-centrin antibodies shows that blepharoplasts fail to form after the arrest of cell divisions. (a) HU-treated gametophytes, fixed 8 hours after imbibition, and labeled with anti-ß-tubulin antibody reveal a random distribution of the antigen in the absence of cell divisions. (b) HU-treated gametophytes, fixed 8 hours after imbibition, and labeled with anti-centrin antibody reveal a random distribution of the antigen in the absence of cell divisions. (c,d) Gametophytes treated with cyclin B dsRNA (c) or treated with olomoucine (d) and labeled with anti-centrin antibody, also show a random distribution of the antigen. (Aggregation of the antigen would be indicative of the formation of blepharoplasts or a motile apparatus – see text.) (e,f) Gametophytes, treated with cyclin A dsRNA and labeled with anti-centrin antibody (e) or anti-ß-tubulin antibody (f) show no aggregation of either antigen. (Antigen aggregation would be indicative of the formation of blepharoplasts or a motile apparatus.) Each micrograph is a reflected light confocal image stack superimposed upon a transmitted DIC image as described in Materials and Methods. Bar, 25 µm.
