Nucleolus organizer regions in human lymphocytes as studied with premature chromosome condensation.
Non-stimulated human lymphocytes from peripheral blood usually contain only one ring-shaped nucleolus. Polyethyleneglycol-mediated cell fusion with mitotic Chinese hamster ovary cells induces premature chromosome condensation in human lymphocytes. Subsequent silver staining reveals that more than one nucleolus organizer region (NOR) is silver-positive and frequently participates in the formation of "satellite associations". It can therefore be concluded that more than one NOR contributes to the ring-shaped nucleoli of lymphocytes in human peripheral blood and that they may be transcriptionally active. During phytohemagglutinin (PHA) stimulation, the number of silver-positive NORs, the number of nucleoli and the number of chromosomes participating in "satellite associations" increase.
Wachtler
F
F
Histologisch-Embryologisches Institut, Wien, Austria.
Roubicek
C
C
Schedle
A
A
Mosgöller
W
W
Bretis
G
G
Schwarzacher
H G
HG
D002877:Chromosomes, Human / Q000648:ultrastructure*; D004276:DNA, Satellite / Q000648:ultrastructure; D006801:Humans; D007621:Karyotyping; D008214:Lymphocytes / Q000648:ultrastructure*; D009697:Nucleolus Organizer Region / Q000648:ultrastructure*; D012834:Silver; D013194:Staining and Labeling
D004276:DNA, Satellite; D012834:Silver