High resolution of a daughter micronucleus in anaphase of a dividing cell of Didinium nasutum. The chromosomes are compacted into one large heterochromatic body. Remnants of the mitotic division spind...

High resolution view of the nuclear envelope of both the macronucleus, seen here, and the micronucleus consists of 2 membranes containing numerous perforations called pores. Proteins are imported thro...

The nuclear envelope of both the macronucleus, seen here, and the micronucleus consists of 2 membranes containing numerous perforations called pores. Proteins are imported through these pores and ribo...

A freeze-fractured view of the nuclear envelope. The fracture in the middle of the figure exposes the cytosolic facing membrane. This can be distinguished by a fractured cytoplasmic organelle at the t...

Transmission electron micrographs showing the unusual nucleolar structures in Sertoli cells of ruminants, with varying numbers of vesicles and tubules; the upper panel illustrates such an organization...

Shown is an image of a thin section showing the ultrastructure of the nucleus and nuclaer envelope in fibroblast from a Hutchinson-Gilford Progeria syndrome patient which carries a mutation in the gen...

Transmission electron micrograph of the salivary gland of the tick Rhipicelphals appendiculatus illustrating the dramatic difference in nuclear size seen in different cell types. Here, the large (prob...

Transmission electron micrograph of nucleus showing the characteristic features of glutaraldehyde fixation introduced as a primary fixative in 1962 and since used routinely. Chromatin appears differen...

Transmission electron micrograph illustrating the accumulation of dense heterochromation that accompanies terminal differentiation in may cells. Shown here is a section through a polychromatophilic er...

Upper panel shows a transmission electron micrograph featuring the nuclear envelope with the nuclear lamina seen here as a uniform layer between the inner nuclear membrane and more darkly staining blo...