Fig. 1

Immunogold electron micrographs of Nardilysin in wild-type mouse in round and elongated spermatids. a In pachytene spermatocytes the cluster of microtubule is unlabelled (X 61 000). b In round spermatid at step 2–3 cytoplasmic microtubules are decorated by gold particles (X 60 000). c Step7 spermatid showing typical nucleus (N), acrosomic granule associated with the Golgi apparatus (G) and at the opposite face the pair of centrioles (Ce). The cytoplasm contains few gold particles (X 12 000). d High magnification of an abnormal step 6–7 spermatid which contains cytoplasmic labelling as also some particles over the growing flagellum (arrow) (X 25 000). e Step 13 spermatid revealing the elongated nucleus (N) and the caudally located cytoplasm surrounding the flagellum. If the cytoplasm contains some NRD convertase particles, the microtubule manchette (m) is strongly labelled (arrows), as also the distal centriole (arrow). No labelling was present over the mitochondria (X 14 000). In the Inset, at the same step, the gold particles are distributed over the axoneme, the periaxonemal vesicles and the anlagen of the fibrous sheath (arrowhead) (X 31 000)