nucleolar organizer regions (nor) are defined as nucleolar components containing a set of argyrophilic proteins which are selectively stained by colloidal silver nitrate staining. although studies have shown that the number of nor dots or particles is directly related to the rapidity of cell proliferation in cancer cells, prognostic or diagnostic value of nor remains controversial. the aim of t...

introduction: nucleolar organizer region associated proteins are a group of non histone proteins which act in r-dna transcription and r-rna processing. the amount of these proteins increase in transition from g1 to s phase in cell cycle. hence these proteins can show the proliferative index of the cells. material & methods: for this purpose 40 patients (30 gastritis, 10 carcinoma) with average ...

Simple polymorphisms in ribosomal DNA repeats in the nucleolus organizer region (NOR) permitted the development of markers for the genetic mapping of the soybean NOR. The markers map to the top end of soybean linkage group F, one of either telomeric end predicted in the cytogenetic and primary trisomic studies.

found in iran, alburnoides bipunctatus and alburnus filippii. the chromosomes of these species were compared using giemsa staining and silver-staining (ag) techniques to describe the karyotypes. both species possess 2n = 50 chromosomes with no detected sex heteromorphism. the karyotypes were distinct, composed of 7 pairs of metacentric, 10 pairs of submetacentric, and 8 pairs of subtelo-acrocen...

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...