Electron microscope studies on spermatids in Conocephalum conicum by freeze-fracture replicas and ultrathin sections.

Abstract

The fine structure of the spermatid in Conocephalum conicum has been studied comparatively by freeze-fracture replicas and ultrathin sections by means of transmission electron microscope. Chromatin fibrils in the nucleus offered the beaded like shape consisting of 10-25nm, granules. The distribution of the pore complexes in the nuclear envelope was localized in partly; and the intercalated particles were denser in the inner membrane of nuclear envelope. The intrastructure of cytoplasmic organelles, Golgi complex and intravacuolar vesicles have been reseached. The intravacuolar vesicles, similar to the lysosome, were examined by size and distribution of intramembrane particles in the fractured membrane.The base (the spline) of the blepharoplast was revealed as layered structure by freeze-fracturing at an oblique direction. And the mark of the filamentous appendage remained in the cell membrane. It is thought that the filamentous appendage develops along some region of the cell membrane. Freeze-fractured flagellum has the enclosed membrane intercalated by particles. The cell wall surrounding two spermatids which developed from a spermatid mother cell, consists of two layers. Its outer layer is made up of cellulose microfibrils. The septum between sister spermatids showed the microfibrillar network pattern.