Presence of basic proteins and ribonucleoproteins in the neck region of human spermatids and spermatozoa.

The ultrastructural cytochemical study of the neck region of human spermatids and spermatozoa revealed that, besides the centrioles, the basal plate, the lateral cupshaped junction body and the annulus material showed affinity for both ethylene diamine tetra-acetic acid (EDTA) stain (a preferential staining method for ribonucleoproteins) and ethanolic phosphotungstic acid (PTA) stain (for cellular localisation of basic proteins). The capitulum and the surface of the striated columns were also stained with ethanolic PTA. The chromatoid body and annulate lamellae-which were frequently encountered in the neck region--stained with both EDTA and ethanolic PTA techniques. This suggests a possible participation of the chromatoid body and annulate lamellae in the formation of the neck region structures.