The signal associated with manchettes became less evident and eventually disappeared. The linear tracts of fluorescence in Sertoli cells were well established at stages when spermatids were at their deepest point in the epithelium (stage V, Fig. 5C). At stage VII (Fig. 5D), when spermatids had completed their translocation to the apex of the epithelium, intense fluorescence persisted in Sertoli cell cytoplasm surrounding spermatid heads and was also present more basally in columnar portions of the cells. After sperm release, this fluorescence pattern disappeared. proventil inhaler
Distribution of IC74 Immunoreactivity in Spermatogenic Cells
The immunological probe for the intermediate chain of cytoplasmic dynein reacted with two regions in spermato-genic cells. The first was the manchette (Fig. 6, A and B, Fig. 7, A and B), and the second was an area along the dorsal curvature of the spermatid head. The latter was not consistently evident in sections, but was better resolved in epithelial fragments (Fig. 3C, arrows) and in isolated spermatids (Fig. 7, A and B). This staining was clearly distinct from that in attached or associated Sertoli cell cytoplasm and was present in spermatids where junction plaques had detached. It was present in elongate spermatids but was absent in mature cells. The exact position of this signal within spermatids was not established.
FIG. 6. Localization of IC74 immunoreactivity to the manchette. Shown here are magnified views of spermatogenic cells within fixed frozen sections of rat seminiferous epithelium that were reacted with an immunological probe for cytoplasmic dynein. The spermatids shown in A (paired fluorescence and phase micrographs) were in the initial stages of elongation. The spermatids in B were at a later stage of differentiation. At both stages, the man-chettes were clearly immunoreactive. Notice that, at these stages of spermatogenesis, Sertoli cell regions associated with the developing head regions of the spermatids were not detectably immunoreactive.
FIG. 7. Shown here is a spermatid that was mechanically dissociated from a perfusion-fixed testis and labeled with an antibody to the intermediate chain of cytoplasmic dynein (green) and with a fluorescent phal-lotoxin (red) that binds to filamentous actin. The labeled actin is in the Sertoli cell junction plaque that remains attached to the spermatid. At this stage of spermatogenesis, immunoreactivity with the dynein antibody occurred mainly within the spermatid itself and primarily was associated with the manchette. Immunoreactivity also occurred within the cell as a linear tract in ”dorsal” regions of the head (asterisk in A). Panel A is the fluorescent image and B is the paired phase image.