Fig. 9. MT scaffold around growing nematocysts in the early (A-C) and late (D-H') growth phase of nematocyst morphogenesis. (A,D) Localization of tubulin in Hydra macerates. (B,C,E,F) Confocal microscopy of nematocyst nests in the body of Hydra whole mounts stained by mAb H22 and mAb anti-tubulin or minicollagen and anti-tubulin (all shown as projections). The putative position of the MTOC is indicated by an arrow. (G-H') EM sections through the outer tubule (ot). (G) Tangential section of the outer tubule (see white box in E). The pair of centrioles (ce) are found at the tip of the tubule. MTs are running parallel to the tubule (yellow arrows). (H) Cross-section of the tubule, the enlargement in H' shows the intimate association of MTs with the membrane around the outer tubule. Bars, 5 µm (A-F); 0.5 µm (G); 2 µm (H); 100 nm (E').