Contrasts in radiation-induced mutation rates at different meiotic stages.
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The genetic stability of normal and neoplastic lymphocytes was compared by using base-line mutation frequency and mutation rate/cell generation. Mutations at the hypoxanthine-guanine phosphoribosyltransferase locus were studied by enumerating thioguanine-resistant cells in a clonogenic assay. The base-line ("spontaneous") mutation frequency was 1.52 X 10(-6), 6.38 X 10(-6), and 1.06 X 10(-6) for normal cells from three individuals and was 1.16 X 10(-3), 6.08 X 10(-5), and 3.06 X 10(-5) for the three malignant cell lines, Jurkat (JM), HRIK, FMC-Hu1B, respectively. The mutation cell/generation rate was 24.6 X 10(-8), 15 X 10(-8), and 5.5 X 10(-8) for lymphocytes from the three normal individuals, and 666.4 X 10(-8), 52.8 X 10(-8), and 131 X 10(-8) for the three malignant cell lines. The results suggest that neoplastic lymphocytes are more genetically unstable than normal lymphocytes.
Explore the source record for details and available documents.
The expectations of the average number of nucleotide differences per site (pi), the proportion of segregating site (s), the minimum number of mutations per site (s*) and some other quantities were derived under the finite site models with and without rate variation among sites, where the finite site models include Jukes and Cantor's model, the equal-input model and Kimura's model. As a model of rate variation, the gamma distribution was used. The results indicate that if distribution parameter alpha is small, the effect of rate variation on these quantities are substantial, so that the estimates of theta based on the infinite site model are substantially underestimated, where theta = 4Nv, N is the effective population size and v is the mutation rate per site per generation. New methods for estimating theta are also presented, which are based on the finite site models with and without rate variation. Using these methods, underestimation can be corrected.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Three genetically distinct types of chicken sarcoma virus Bratislava 77 (B77 virus) differing in their ability to infect duck cells were identified. B77 virus type I does not infect duck cells; B77 virus type II has a low efficiency of infection of duck cells; and B77 virus type III has a high efficiency of infection of duck cells. B77 viruses type I and III are produced by spontaneous mutation during the growth of B77 virus type II in chicken cells. The spontaneous mutation of B77 virus type II TO B77 virus type III occurs with a high rate (approximately 1 mutation per 50 infected cell generations), requires cell replication, and neither occurs during the synthesis of viral DNA on an RNA template nor during the transcription of progeny viral RNA from the provirus. The rate of spontaneous mutation of B77 virus type II to B77 virus type I is greater than the rate of spontaneous mutation of B77 virus type II to B77 virus type III.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.