T antigen banding on chromosomes of simian virus 40 infected muntjac cells.
Chromosomes were prepared from mitotic munjac cells 48 to 72 h after infection with SV40 virus. When stained for SV40 T antigen by indirect immunofluorescence, all chromosomes within an infected cell were fluorescent, indicating the presence of T antigen. Furthermore, the chromosomes were not uniformly stained but appeared to have regions of high and low fluorescence intensity. A variety of controls showed that the banding patterns are specific and highly reproducible and may indeed reflect the binding sites of T antigen. The bright, fluorescent bands T antigen were found to correspond to bands visualized by trypsin-Giesma staining (G-bands) and also by quinacrine staining (Q-bands). Current knowledge of chromosome banding indicates that Q-bands reflect the distribution of AT-rich regions along the chromosome. From the DNA sequence of SV40, it is known that one of the T antigen binding sites contains AT-rich sequences; thus, T antigen banding might be due to the base-specific binding of T antigen to chromatin. In addition, these bands have been implicated as centers for chromosome condensation and units in control of DNA replication. While the functional significance of T antigen binding has yet to be determined, the SV40-muntjac system provides an unusual opportunity to study the interaction of a known regulatory protein with mammalian chromosomes.
D000818:Animals; D000956:Antigens, Viral; D001666:Binding Sites, Antibody; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D002871:Chromosome Banding; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis; D003670:Deer; D000939:Epitopes; D005455:Fluorescent Antibody Technique; D008677:Metaphase; D013539:Simian virus 40 / Q000276:immunology; D013194:Staining and Labeling; D014779:Virus Replication
D000956:Antigens, Viral; D004279:DNA, Viral; D000939:Epitopes