Transmission electron micrograph of rat liver cell showing a grazing section through the nuclear envelope and illustrating the high density of nuclear pores in cells from a 1 day old animal. The cytop...

Transmission electron micrographs showing details of nuclear pores in thin sections of an erythroblast (above) and endothelial cell (below). Pores appear to be filled with dark staining material in th...

Transmission electron micrograph of surface of nuclear envelope of guinea pig spermatocyte prepared by the Freeze-fracture technique shows the unusual clustering of nuclear pores in these cells. From...

Transmission electron micrograph of stacked annulate lamellae from the oocyte of the sea urchin Arbacia. Annulate lamellae consist of sheets of membrane containing closely packed structures resemblin...

High resolution image of the macronucleus of Coleps hirtus. Heterochromatin and nucleoli are seen as smaller and larger stained bodies, respectively, in the macronucleus. Many nuclear pores exist in t...

Nuclear pores are clearly seen in these transmission electron micrographs of cells after cryo-fixation, freeze-fracture and surface replication. Upper panel shows the outer surface of of the nuclear e...

Grazing thin section through the nuclear envelope of a macronucleus. Nuclear pores are packed so tightly that they often form a hexagonal array with 6 pores surrounding a central pore. The pores often...

Transmission electron micrographs of sections of tadpole oocyte show the potential for exchange between the nucleus and the cytoplasm at the nuclear envelope. Thin filaments that appear to traverse nu...

Transmission electron micrograph illustrating the unusually prominent fibrous nuclear lamina (arrows) seen in many invertebrates such as this leech ganglion cell. From Fawcett (1966) Am J. Anat. 119:...

High resolution image of the macronucleus of Coleps hirtus. Heterochromatin and nucleoli are seen as smaller and larger stained bodies, respectively, in the macronucleus. Many nuclear pores exist in t...