title: Frequency of satellite association of human chromosomes is correlated with amount of Ag-staining of the nucleolus organizer region.
abstract: Methaphase chromosomes from karyotypically normal adult humans (three males, six females) and one male with a 13p - chromosome were stained by quinacrine and then by the Ag-AS silver staining method to reveal nucleolus organizer regions (NORs). Each person had a characteristic number of Ag-stained chromosomes per cell, always fewer than 10. Determination of the mean Ag-size of each chromosome showed that each of the 10 individuals had a unique distribution of Ag-stain. Within each individual, there was some variation from cell to cell in the number of acrocentric chromosomes that were Ag-stained; this was not random, and the same chromosomes (those that had at most a small amount of Ag-stain) tended to be unstained in every cell. Satellite associations were scored on the same cells. Chromosomes that had no Ag-stain were involved in satellite association less than 20% as often as those that had some Ag-stain. Chromosomes that had a small amount of Ag-stain were involved in association about 50% as often as those that had a large amount of stain. Regression analysis of the 50 (of a total of 100) acrocentric chromosomes which could be individually identified by quinacrine markers showed that the frequency with which a chromosome was involved in satellite association was strongly correlated with the amount of Ag-stained material in the NOR.
mesh_terms: D002466:Cell Nucleolus; D002872:Chromosome Deletion; D002875:Chromosomes / Q000648:ultrastructure*; D003584:Cytological Techniques; D004247:DNA; D004276:DNA, Satellite; D005260:Female; D006801:Humans; D007621:Karyotyping; D008297:Male; D011796:Quinacrine; D012834:Silver; D013194:Staining and Labeling
chemical_list: D004276:DNA, Satellite; D012834:Silver; D004247:DNA; D011796:Quinacrine