Detection of fibrillarin in nucleolar remnants and the nucleolar matrix.
In order to gain further insights into the fundamental structure of the nucleolus, nucleolar remnants of Xenopus and chickens were examined for the presence of fibrillarin and nucleolus organizer region (NOR) silver staining. Nucleolar remnants of Xenopus nucleated red blood cells were found to contain easily detectable amounts of fibrillarin and NOR silver staining. Upon examination of various tissues, fibrillarin and NOR silver staining were detected in nucleoli of Xenopus liver hepatocytes and within nucleoli of oocytes and follicle cells from ovaries of mature female toads. By comparison, nucleolar remnants of adult chicken nucleated red blood cells contained only trace amounts of fibrillarin and NOR silver staining, whereas red blood cell nucleolar remnants of immature chicks had easily detectable amounts of fibrillarin and NOR silver staining. Nucleoli from hepatocytes of both adult and immature chickens demonstrated comparable levels of fibrillarin and NOR silver staining. Since fibrillarin was found in nucleolar remnant structures, we tested for (and detected) its presence in residual nucleoli of in situ nuclear matrix derived from HeLa cells. These findings are discussed in terms of the basic structural and functional organization of the nucleolus.
Ochs
R L
RL
W.M. Keck Autoimmune Disease Center, La Jolla, California 92037.
Smetana
K
K
D000818:Animals; D002466:Cell Nucleolus / Q000648:ultrastructure*; D002478:Cells, Cultured; D002645:Chickens; D002868:Chromosomal Proteins, Non-Histone / Q000032:analysis*; D004912:Erythrocytes / Q000648:ultrastructure; D005260:Female; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D008099:Liver / Q000648:ultrastructure; D008854:Microscopy, Electron / Q000379:methods; D015530:Nuclear Matrix / Q000648:ultrastructure; D009697:Nucleolus Organizer Region / Q000648:ultrastructure*; D009865:Oocytes / Q000648:ultrastructure; D012261:Ribonucleoproteins / Q000032:analysis; D014982:Xenopus laevis
D002868:Chromosomal Proteins, Non-Histone; D012261:Ribonucleoproteins; C047458:fibrillarin