FINE-STRUCTURAL OBSERVATION OF A NUCLEOLAR-NUCLEAR MATRIX-LAMINA-INTERMEDIATE FILAMENT SYSTEM IN TRANSFORMED-CELLS

The nuclear matrix is a nonchromatin structure of the nucleus normally concealed by a much :larger mass of chromatin. Several methods have b een developed to remove chromatin from nucleus while preserving the un derlying matrix architecture to some degree. The present study showed that after extraction of PtK2 cells and cervical carcinoma cells (CC3) with Triton X-100, ammonium sulfate and DNase, the nucleolar-nuclear matrix-intermediate filament (Nu-Nm-C-IF) network remained. The nucleo lus was oval in shape and appeared as a fibrillar mass with an accentr ic dense fibrillar centre. This nucleolar skeleton was in direct conne ction with the nuclear matrix which in turn is connected with cytoplas mic intermediate filaments by lamins. It is concluded from these obser vations that the Nu-NM-L-IF system forms a continuous system which pla ys an important role in. the maintenance of the nucleolar, nuclear and cytoplasmic integrity and cellular function.