NUCLEAR PORE COMPLEX IN SPERMATOGENESIS OF BEIJING DOMESTIC DUCK——ELECTRON MICROSCOPE OBSERVATION OF FREEZE-ETCHING

The nuclear pore complex in spermatogenesis of Beijing domestic duck has been studiedby means of electron microscopic observation of freeze-etching. The structure of the poreobserved proves to be in accord with the model of the nuclear pore complex proposed respec-tively by Franke (1970) and Roberts et al. (1970). But its central granule may be present(1--3 granules) or absent. The granules are considered to be material in transit. The sizeand frequency of the pore vary with different types of reproductive cells, which is believedto be related to the cells' function. The pores concentrate on the side of nucleus near Golgizone in primary spermatocyte and near the proacrosome of spermatid, and this shows thefunctional variety of parts in the nucleus.