PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 14472429

Papova virus group.

J L MELNICK
View original source ↗Export metadata ↓

Abstract

The papilloma, polyoma, and vacuolating agents seem to form a natural group of tumor viruses, for which the name papova virus group is proposed. Members of the group have the following properties: 45 mmicro diameter, deoxyribonucleic acid core, 42 capsomeres, absence of essential lipids, thermal resistance, slow growth cycle with multiplication within the cell nucleus, and tumorigenicity.

Explore related subjects

Cell NucleusDNADNA VirusesHumansLipidsNeoplasmsVirionVirusesNEOPLASMS/virologyVIRUSESJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J L MELNICK. 1962-03-30. Papova virus group.. https://doi.org/10.1126/science.135.3509.1128

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2025

Decoding ALS from the tail end of RNA.

In this issue of Cell Genomics, McKeever et al.1 generate a single-nucleus transcriptomic atlas of ALS/FTLD brain and reveal widespread alternative polyadenylation changes. Their findings highlight 3' end RNA processing as a central integrator of stress responses, cell-type specificity, and disease susceptibility, offering new mechanistic insight and potential therapeutic directions.

Cell Nucleus↗
PubMed2007

Cyclin A2 regulates nuclear-envelope breakdown and the nuclear accumulation of cyclin B1.

Mitosis is thought to be triggered by the activation of Cdk-cyclin complexes. Here we have used RNA interference (RNAi) to assess the roles of three mitotic cyclins, cyclins A2, B1, and B2, in the regulation of centrosome separation and nuclear-envelope breakdown (NEB) in HeLa cells. We found that the timing of NEB was affected very little by knocking down cyclins B1 and B2 alone or in combination. However, knocking down cyclin A2 markedly delayed NEB, and knocking down both cyclins A2 and B1 delayed NEB further. The timing of cyclin B1-Cdk1 activation was normal in cyclin A2 knockdown cells, and there was no delay in centrosome separation, an event apparently controlled by the activation of cytoplasmic cyclin B1-Cdk1. However, nuclear accumulation of cyclin B1-Cdk1 was markedly delayed in cyclin A2 knockdown cells. Finally, a constitutively nuclear cyclin B1, but not wild-type cyclin B1, restored normal NEB timing in cyclin A2 knockdown cells. These findings show that cyclin A2 is required for timely NEB, whereas cyclins B1 and B2 are not. Nevertheless cyclin B1 translocates to the nucleus just prior to NEB in a cyclin A2-dependent fashion and is capable of supporting NEB if rendered constitutively nuclear.

Cell Nucleus↗
PubMed2007

Phylogenetic analysis of AA-genome Oryza species (Poaceae) based on chloroplast, mitochondrial, and nuclear DNA sequences.

Species in the genus Oryza (Poaceae) contain 10 genomic types and are distributed in pan-tropics of the world. To explore phylogenetic relationships of Oryza species having the AA-genome, DNA sequences of the chloroplast trnL intron and trnL-trnF spacer, mitochondrial nad1 intron 2, and nuclear internal transcribed spacer were analyzed, based on materials from 6 cultivated (O. sativa and O. glaberrima) and 13 wild accessions, in addition to a CC-genome species (O. officinalis) that was used as an outgroup. Analyses of the combined sequence data set from different sources provide a much better resolution of the AA-genome species than the individual data set, indicating the limitation of a single gene in phylogenetic reconstruction. The phylogeny based on the combined data set demonstrated an apparent grouping of the AA-genome Oryza species that was well associated with their geographic origin, although the Australian O. meridionalis showed its affinity with the African species. The geographic pattern of the phylogenetic relationship was probably attributed to the frequent genetic exchange and introgression among the AA-genome species from the same continents. In addition, Asian cultivated rice O. sativa showed its close relation to O. rufipogon and O. nivara, whereas African cultivated rice O. glaberrima was closely linked to O. barthii and O. longistaminata, indicating the independent domestication of the two cultivated species in different geographic locations.

Cell Nucleus↗