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Differentiation; Research in Biological... 1981The effects of aphidicolin - a powerful inhibitor of DNA polymerase alpha and of DNA replication - on normal development and on differentiation without cleavage of...
The effects of aphidicolin - a powerful inhibitor of DNA polymerase alpha and of DNA replication - on normal development and on differentiation without cleavage of Chaetopterus eggs have been studied with cytological, cytochemical, and biochemical methods. The experiments show that the initial period of pseudocleavage can take place in the absence of nuclear DNA synthesis, but further development (segregation, hatching, ciliation) requires DNA synthesis. However ciliated unicellular larvae can be obtained under conditions where the DNA content of the embryos in only 40% of the controls. In fertilized eggs, aphidicolin immediately stops cleavage. The significance of these results is discussed.
Topics: Animals; Aphidicolin; Cell Differentiation; DNA; DNA Replication; Diterpenes; Larva; Polychaeta; Time Factors
PubMed: 6799347
DOI: 10.1111/j.1432-0436.1981.tb01126.x -
Cytogenetics and Cell Genetics 1993Aphidicolin (APC)-sensitive fragile sites were identified in chromosome preparations from peripheral lymphocyte cultures of 12 four-way crossbred pigs. A chi 2 analysis...
Aphidicolin (APC)-sensitive fragile sites were identified in chromosome preparations from peripheral lymphocyte cultures of 12 four-way crossbred pigs. A chi 2 analysis demonstrated that aphidicolin-induced breakage events and previously reported in vivo chromosome rearrangement events were not independent. Comparison of expected Poisson and negative binomial distributions to observed breakage patterns indicated that the negative binomial distribution provided a better fit to experimental data. The negative binomial distribution is consistent with a distribution of breakage rates, i.e., non-constant rates of breakage at chromosomal loci across the genome.
Topics: Animals; Aphidicolin; Binomial Distribution; Chi-Square Distribution; Chromosome Aberrations; Chromosome Banding; Chromosome Fragile Sites; Chromosome Fragility; Dose-Response Relationship, Drug; Female; Lymphocytes; Male; Mutagens; Poisson Distribution; Swine; Translocation, Genetic
PubMed: 8428508
DOI: 10.1159/000133452 -
Eukaryotic Cell Apr 2008Giardia intestinalis is a ubiquitous intestinal protozoan parasite and has been proposed to represent the earliest diverging lineage of extant eukaryotes. Despite the...
Giardia intestinalis is a ubiquitous intestinal protozoan parasite and has been proposed to represent the earliest diverging lineage of extant eukaryotes. Despite the importance of Giardia as a model organism, research on Giardia has been hampered by an inability to achieve cell cycle synchrony for in vitro cultures. This report details successful methods for attaining cell cycle synchrony in Giardia cultures. The research presented here demonstrates reversible cell cycle arrest in G(1)/S and G(2)/M with aphidicolin and nocodazole, respectively. Following synchronization, cells were able to recover completely from drug treatment and remained viable and maintained synchronous growth for 6 h. These techniques were used to synchronize Giardia cultures to increase the percentages of mitotic spindles in the cultures. This method of synchronization will enhance our ability to study cell cycle-dependent processes in G. intestinalis.
Topics: Animals; Aphidicolin; Cell Cycle; Cell Survival; Enzyme Inhibitors; Flow Cytometry; Giardia lamblia; Nocodazole; Tubulin Modulators
PubMed: 18296622
DOI: 10.1128/EC.00415-07 -
Developmental Biology Nov 1986Aphidicolin, an inhibitor of DNA polymerase alpha, blocks DNA synthesis and cell division in sea urchin embryos. The effects of this inhibition appear to be stage...
Aphidicolin, an inhibitor of DNA polymerase alpha, blocks DNA synthesis and cell division in sea urchin embryos. The effects of this inhibition appear to be stage dependent. Blastulae treated with aphidicolin before the thickening of the vegetal plate undergo developmental arrest prior to gastrulation. The extent of inhibition of DNA synthesis varies from 60 to 93% in these embryos. However, when aphidicolin is added after the vegetal plate has thickened, development continues normally through pluteus formation, even though DNA synthesis is inhibited by greater than or equal to 90% and cell division has ceased. These observations indicate that, from the vegetal plate stage onward, morphogenesis and overt differentiation are independent of DNA synthesis and cell division.
Topics: Animals; Aphidicolin; Autoradiography; Cell Differentiation; Cell Division; DNA; Diterpenes; Morphogenesis; Sea Urchins
PubMed: 3095164
DOI: 10.1016/0012-1606(86)90073-4 -
Human Genetics Feb 1988
Topics: Aphidicolin; Chromosome Fragile Sites; Chromosome Fragility; DNA Polymerase II; DNA Repair; Diterpenes; Humans
PubMed: 3123359
DOI: 10.1007/BF00278199 -
Antimicrobial Agents and Chemotherapy Jan 2001Aphidicolin and a series of semisynthetic aphidicolan derivatives have been identified in in vitro tests as novel drugs with antiparasitic potential. All compounds have...
Aphidicolin and a series of semisynthetic aphidicolan derivatives have been identified in in vitro tests as novel drugs with antiparasitic potential. All compounds have been tested against extracellular promastigotes of Leishmania donovani, L. infantum, L. enriettii, and L. major and against intracellular amastigotes of L. donovani in murine macrophages. The compounds showed antileishmanial activity at concentrations in the microgram range (50% effective concentration [EC(50)] = 0.02 to 1.83 microg/ml). The most active derivative (aphidicolin-17-glycinate hydrochloride) had EC(50)s of 0. 2 microg/ml against extracellular and 0.02 microg/ml against intracellular L. donovani parasites. To validate the pharmacological potential of tested drugs, pharmacological safety was determined by testing all compounds against two neoplastic cell lines (squamous carcinoma [KB] and melanoma [SK-Mel]) and against murine bone marrow-derived macrophages as host cells. With minor exceptions only for macrophages, tested aphidicolans did not show significant cytotoxicity (EC(50) > 25.0 microg/ml). Structure-activity relationships of these aphidicolan derivatives are discussed.
Topics: Animals; Antiprotozoal Agents; Aphidicolin; Bone Marrow Cells; Cell Survival; Culture Media; Humans; Leishmania; Mice; Structure-Activity Relationship; Tumor Cells, Cultured
PubMed: 11120979
DOI: 10.1128/AAC.45.1.288-292.2001 -
Mutagenesis Mar 2013The comet assay is increasingly used to measure the repair of various types of DNA damage. Modifications of the standard protocol have been introduced to determine the...
The comet assay is increasingly used to measure the repair of various types of DNA damage. Modifications of the standard protocol have been introduced to determine the repair capacity of specific DNA repair pathways by the removal of pathway-specific DNA lesions. Recently, a cellular phenotype assay for nucleotide excision repair (NER) by quantifying the DNA strand breaks after in vitro challenge of peripheral blood mononucleated cells with benzo[a]pyrene diol epoxide (BPDE) in the presence or absence of the DNA polymerase inhibitor aphidicolin (APC) was developed (Vande Loock, K., Decordier, I., Ciardelli, R., Haumont, D. and Kirsch-Volders, M. (2010) An aphidicolin-block nucleotide excision repair assay measuring DNA incision and repair capacity. Mutagenesis, 25, 25-32). Individual repair capacity (RC) was defined as the amount of DNA damage induced by BPDE in the presence of APC minus the damage induced by BPDE and APC alone. This value should mainly reflect the incision capacity of the NER enzymes. Following this approach, we investigated the RC of cultured isolated peripheral blood mononuclear cells of nine donors in repeated experiments. We also performed the same experiments with peripheral whole blood cultures from these donors. Our results indicated considerable intra- and inter-individual variability and substantial differences between the RC of isolated mononuclear cells and whole blood from the same donor. Furthermore, the RC of unstimulated blood did not differ significantly from the repair capacity of stimulated blood but also showed considerable inter-individual variability. Altogether, our results suggest that there is still need for standardisation and validation of this assay before it can be reliably used in human biomonitoring studies.
Topics: 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; Adolescent; Adult; Aphidicolin; Benzo(a)pyrene; Comet Assay; DNA Damage; DNA Repair; Enzyme Inhibitors; Female; Humans; Leukocytes, Mononuclear; Male; Reproducibility of Results; Young Adult
PubMed: 23221037
DOI: 10.1093/mutage/ges063 -
Biochemical Society Transactions Feb 1992
Topics: Animals; Aphidicolin; Camptothecin; Cell Cycle; Cell Death; Dactinomycin; Drug Resistance; Hybridomas; T-Lymphocytes
PubMed: 1634006
DOI: 10.1042/bst020084s -
Oncogene Sep 2004Fragile sites are classified as common or rare depending on their occurrence in the populations. While rare sites are mainly associated with inherited diseases, common...
Fragile sites are classified as common or rare depending on their occurrence in the populations. While rare sites are mainly associated with inherited diseases, common sites have been involved in somatic rearrangements found in the chromosomes of cancer cells. Here we study a mouse locus containing the ionotropic glutamate receptor delta 2 (grid2) gene in which spontaneous chromosome rearrangements occur frequently, giving rise to mutant animals in inbred populations. We identify and clone common fragile sites overlapping the mouse grid2 gene and its human ortholog GRID2, lying respectively at bands 6C1 and 4q22 in a 7-Mb-long region of synteny. These results show a third example of orthologous common sites conserved at the molecular level, and reveal an unexpected link between an inherited disease and an aphidicolin-sensitive region. Recurrent deletions of subregions of band 4q22 have been previously described in human hepatocellular carcinomas. This 15-Mb-long region appears precisely centered on the site described here, which strongly suggests that it also plays a specific role in hepatic carcinogenesis.
Topics: Animals; Aphidicolin; Chromosome Aberrations; Chromosome Fragile Sites; Chromosome Mapping; Chromosomes, Human, Pair 4; Conserved Sequence; Genetic Diseases, Inborn; Humans; In Situ Hybridization, Fluorescence; Liver Neoplasms; Loss of Heterozygosity; Mice; Receptors, Glutamate
PubMed: 15286716
DOI: 10.1038/sj.onc.1207809 -
Molecular & General Genetics : MGG May 1995Using a genetic approach, Chinese hamster ovary (CHO) cells sensitive (aphS) and resistant (aphR) to aphidicolin were grown in the presence or absence of various DNA...
Using a genetic approach, Chinese hamster ovary (CHO) cells sensitive (aphS) and resistant (aphR) to aphidicolin were grown in the presence or absence of various DNA polymerase inhibitors, and the newly synthesized DNA isolated from [32P]dNMP-labelled, detergent-permeabilized cells, was characterized after fractionation by gel electrophoresis. The particular aphR mutant CHO cell line used was one selected for resistance to aphidicolin and found to possess an altered DNA polymerase of the alpha-family. The synthesis of a 24 kb replication intermediate was inhibited in wild-type CHO cells grown in the presence of aphidicolin, whereas the synthesis of this replication intermediate was not inhibited by this drug in the mutant CHO cells or in the aphidicolin-resistant somatic cell hybrid progeny constructed by fusion of wild-type and mutant cell lines. Arabinofuranosylcytosine (ara-C), like aphidicolin, inhibited the synthesis of this 24 kb DNA replication intermediate in the wild-type CHO cells but not in the aphR mutant cells. However, carbonyldiphosphonate (COMDP) inhibited the synthesis of the 24 kb replication intermediate in both wild-type and mutant cells. N2-(p-n-Butylphenyl)-2' deoxyguanisine-5'-triphosphate (BuPdGTP) was found to inhibit the formation of Okazaki fragments equally well in the wild-type and mutant cell lines and thus led to inhibition of synthesis of DNA intermediates in both cases. It appears that aphidicolin and ara-C both affect a common target on the DNA polymerase, which is different from that affected by COMDP in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Animals; Aphidicolin; CHO Cells; Cricetinae; Cytarabine; DNA; DNA Polymerase II; DNA Replication; Deoxyguanosine; Diphosphonates
PubMed: 7770054
DOI: 10.1007/BF00293148