Simultaneous ultrastructural localization of Ag-NOR (nucleolar organizer region) proteins and ribonucleoproteins during mitosis, in human breast cancerous tissues.

Ultrastructural localization of nucleolar organizers during oogenesis in Xenopus laevis using a silver technique.

Silver staining at the electron microscopic level of the nucleolar organizers was carried out on Xenopus laevis oocytes at various stages of oogenesis. The results indicate that a positive reaction takes place exclusively in the dense fibrillar component of the extrachromosomal nucleoli. This constituent undergoes morphological changes of distribution and architecture, which have been correlate...

Nucleolar organizer regions in patients with precancerous and cancerous lesions of the uterine cervix.

Nucleolar organizer regions (Ag-NORs) were studied in patients with cervical precancerous and cancerous lesions along with controls. The data revealed a statistically significant decrease of Ag-NORs in cancer patients, as well as in women with severe precancerous lesions as compared with controls. A similar decrease in the amount of Ag-staining was also observed in both cancer and severe dyspla...

Colocalization of coilin and nucleolar proteins in Cajal body-like structures of micronucleated PtK2 cells.

Cajal bodies (CB) are ubiquitous nuclear structures involved in the biogenesis of small nuclear ribonucleoproteins and show narrow association with the nucleolus. To identify possible relationships between CB and the nucleolus, the localization of coilin, a marker of CB, and of a set of nucleolar proteins was investigated in cultured PtK2 cells undergoing micronucleation. Nocodazol-induced micr...

Short communication: Chromosome description and localization of Nucleolus Organizing Regions (NORs) by Ag-staining Technique in Alburnus filippii (Cyprinidae, Cypriniformes) in Anzali Lagoon, North of Iran

Ultrastructural cytochemistry of the nucleus in Zea mays embryos during germination.

The ultrastructure of embryonic root cells of Zea mays was studied from the quiescent stage (dry seed) to 72 h of germination. Semithin and ultrathin sections of tissues fixed with only glutaraldehyde and embedded in Epon were observed after usual section staining and after cytochemical reactions specific for DNA or preferential for ribonucleoproteiNS. In quiescent cells, dense chromatin forms ...