Baculovirus expression system cells expressing v-myb oncogene: the distribution of RNA and DNA in specific nuclear compartments with respect to structures interacting with anti-v-Myb antibody.
The distribution of RNA, total DNA and newly synthesized DNA within nucleoli-like structures in insect cells overexpressing v-myb oncogene was investigated. Three types of these structures which revealed interaction with anti-v-Myb oncoprotein antibody were found at the ultrastructural level. Specific staining by toluidine blue at pH 5.2 showed the presence of RNA in these nucleoli-like structures. To detect total DNA, the in situ terminal deoxynucleotidyl transferase-immunogold technique was used. In addition to an expected labeling of host condensed chromatin, the labeling of the three types of nucleoli-like structures differed from each other. While the compact (type I) and ring-shaped (type II) nucleoli-like structures were labeled only on their periphery and in the proximity of baculovirus particles that interacted with them, the structures with an appearance of nucleolonemas (type III) were labeled strongly. Incorporation of 5-bromo-2-deoxyuridine, in spite of a poor labeling of newly synthesized DNA, confirmed these results. We suggest that the nucleoli-like structures of type I and II are of nucleolar origin. The type III more likely represents virogenic stroma or viral DNA storage site.
Stokrová
J
J
Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague. stokrova@img.cas.cz
Korb
J
J
Dvoráková
M
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001973:Bromodeoxyuridine / Q000378:metabolism; D002451:Cell Compartmentation; D002460:Cell Line; D002466:Cell Nucleolus / Q000737:chemistry / Q000648:ultrastructure; D002467:Cell Nucleus / Q000737:chemistry* / Q000648:ultrastructure; D004261:DNA Replication; D004274:DNA, Recombinant / Q000032:analysis*; D020570:Genes, myb; D005822:Genetic Vectors / Q000235:genetics*; D007150:Immunohistochemistry; D017924:Nucleopolyhedroviruses / Q000235:genetics*; D020626:Oncogene Proteins v-myb / Q000096:biosynthesis* / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D018411:Spodoptera / Q000166:cytology
D000911:Antibodies, Monoclonal; D004274:DNA, Recombinant; D020626:Oncogene Proteins v-myb; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D001973:Bromodeoxyuridine