Fig. 3.

NCSs consist of a unique subset of NPC, and nuclear membrane and lamina proteins. Indirect immunofluorescence on semi-thin frozen sections of human luteal endometrium of antigens clearly present and/or enriched in NCSs (left column: A,C,E,G,I,K,M), of antigens absent from, barely detectable, or only in some NCSs (middle column: B,D,F,H,J,L,N), and of antigens clearly present in NCSs as double fluorescence control (right column: B′,D′,F′,H′,J′,L′,N′). The identity of all antigens is indicated on each panel. NCSs that are not obvious (E) and all in the double fluorescence series (two right columns) are indicated (arrows). In all cases, the identity of NCSs was confirmed by double fluorescence and/or phase-contrast microscopy. Note that although mAb414 recognizes all four nucleoporins, only Nup153 (A) and Nup62 (C) but not Nup358 (B) nor Nup214 (D) are present in NCSs. Tpr is present in only some (F, arrow) but not other NCSs (arrowheads). Of the two inner nuclear membrane and lamina-associated proteins emerin (G) and LAP2β (J), only emerin is enriched in NCSs. Nucleoli, identified by fibrillarin (N, arrowheads), are often adjacent to or surrounding NCSs (N′, arrows) but do not overlap. Note the particularly high enrichment in NCSs of Nup153 (A), emerin (G) and lamin A/C (I), which at this exposure are barely detectable in their usual nuclear envelope locations. Magnification is identical in all panels; scale bar, 5 μm.