Nuclear membrane: rigid and flexible portions. I have noticed for some time that there are differences in the “lay” of the nuclear membrane (that is the inner nuclear membrane). There are stretches of inner nuclear membrane that are rigid looking, generally are devoid of condensed chromatin, still have the lamins present, but the protein groups attached or adjacent to the nuclear lamina of the inner nuclear membrane are spaced at a greater distance than the proteins in places of chromatin condensed along the inner nuclear membrane.  I found this particularly nice area in a guinea pig alveolar type II cell nucleus (which however had been exposed to vinyl chloride for a year), but this is a phenomenon not related to exposure but normal nuclear architecture. Cant wait to do more on this.

Below is an electron micrograph of an alveolar type II cell of a guinea pig, exposed as mentioned above to vinyl chloride, but this is just an image showing the inner nuclear membrane configuration which probably will end up being some kind of annulus around a nuclear pore complex, maybe part of the landscape that prevents condensation of chromatin in the nuclear pore area.