Annulate lamellae in the spermatids of the rat.

In this study the formation and development of annulate lamellae in rat spermatids have been studied by electron microscopy. It first appeared in step 8 spermatids and seemed to be associated with a Golgi complex and the chromatid body. At regular intervals electron dense granular and fibrillar structures associated with pores of the lamellae could be seen. At step 12 of spermiogenesis an extensive membranous system appeared to be formed by the annulate lamellae. The annulate lamellae were present in the spermatids up to late spermiogenesis and were detached from the spermatids together with the residual bodies. High resolution autoradiographic studies with 3H-uridine, 3H-leucine and 3H-arginine did not show any labelling of the annulate lamellae that was significantly higher than in the rest of the cytoplasm.