p53-Independent checkpoint controls in a plant cell model
Allium cepa L. meristems were used as a plant model to study the p53-independent control of S and G2 phases by checkpoint pathways, in eukaryotic cells. Checkpoint blocks were induced at early and mid S by hydroxyurea. After their spontaneous override, cells became accumulated in G2-prophase, giving...
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| Format: | Article |
| Language: | English |
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BMC
2003-01-01
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| Series: | Biological Research |
| Subjects: | |
| Online Access: | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300009 |
| _version_ | 1819036661331263488 |
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| author | HELVIA R PELAYO JUANA PINCHEIRA JUAN F GIMÉNEZ-ABIÁN DUNCAN J CLARKE CONSUELO DE LA TORRE |
| author_facet | HELVIA R PELAYO JUANA PINCHEIRA JUAN F GIMÉNEZ-ABIÁN DUNCAN J CLARKE CONSUELO DE LA TORRE |
| author_sort | HELVIA R PELAYO |
| collection | DOAJ |
| description | Allium cepa L. meristems were used as a plant model to study the p53-independent control of S and G2 phases by checkpoint pathways, in eukaryotic cells. Checkpoint blocks were induced at early and mid S by hydroxyurea. After their spontaneous override, cells became accumulated in G2-prophase, giving rise later on to a delayed mitotic wave. Cell growth was maintained during the checkpoint blocks, as the delayed mitoses were larger in size than the control ones. Under continuous hydroxyurea treatment, the delayed mitotic was formed by two subpopulations: normal mitoses corresponding to cells having properly recovered from the checkpoint block, and abnormal ones resulting from checkpoint adaptation. These latter cells displayed broken chromatids as they had unduly overriden the G2 checkpoint block, without completing DNA repair. The frequency of the checkpoint-adapted mitoses increased with the hydroxyurea concentration from 0.25 to 1.0 mM. However, from 1 mM hydroxyurea upwards, some of the cells lost their competence for checkpoint adaptation. Therefore, the dose of a genotoxic agent that still allows G2 checkpoint adaptation should always be applied in order to get rid of uncontrolled proliferating cells. This is specially suitable for cells lacking a functional p53 protein |
| first_indexed | 2024-12-21T08:09:04Z |
| format | Article |
| id | doaj.art-69606b0cbd134f3eb2763354ccacdfe0 |
| institution | Directory Open Access Journal |
| issn | 0716-9760 0717-6287 |
| language | English |
| last_indexed | 2024-12-21T08:09:04Z |
| publishDate | 2003-01-01 |
| publisher | BMC |
| record_format | Article |
| series | Biological Research |
| spelling | doaj.art-69606b0cbd134f3eb2763354ccacdfe02022-12-21T19:10:42ZengBMCBiological Research0716-97600717-62872003-01-01363-4381388p53-Independent checkpoint controls in a plant cell modelHELVIA R PELAYOJUANA PINCHEIRAJUAN F GIMÉNEZ-ABIÁNDUNCAN J CLARKECONSUELO DE LA TORREAllium cepa L. meristems were used as a plant model to study the p53-independent control of S and G2 phases by checkpoint pathways, in eukaryotic cells. Checkpoint blocks were induced at early and mid S by hydroxyurea. After their spontaneous override, cells became accumulated in G2-prophase, giving rise later on to a delayed mitotic wave. Cell growth was maintained during the checkpoint blocks, as the delayed mitoses were larger in size than the control ones. Under continuous hydroxyurea treatment, the delayed mitotic was formed by two subpopulations: normal mitoses corresponding to cells having properly recovered from the checkpoint block, and abnormal ones resulting from checkpoint adaptation. These latter cells displayed broken chromatids as they had unduly overriden the G2 checkpoint block, without completing DNA repair. The frequency of the checkpoint-adapted mitoses increased with the hydroxyurea concentration from 0.25 to 1.0 mM. However, from 1 mM hydroxyurea upwards, some of the cells lost their competence for checkpoint adaptation. Therefore, the dose of a genotoxic agent that still allows G2 checkpoint adaptation should always be applied in order to get rid of uncontrolled proliferating cells. This is specially suitable for cells lacking a functional p53 proteinhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300009Checkpoint adaptationHydroxyureaS and G2 checkpointsp53-independent checkpointsAllium cepa L. meristems |
| spellingShingle | HELVIA R PELAYO JUANA PINCHEIRA JUAN F GIMÉNEZ-ABIÁN DUNCAN J CLARKE CONSUELO DE LA TORRE p53-Independent checkpoint controls in a plant cell model Biological Research Checkpoint adaptation Hydroxyurea S and G2 checkpoints p53-independent checkpoints Allium cepa L. meristems |
| title | p53-Independent checkpoint controls in a plant cell model |
| title_full | p53-Independent checkpoint controls in a plant cell model |
| title_fullStr | p53-Independent checkpoint controls in a plant cell model |
| title_full_unstemmed | p53-Independent checkpoint controls in a plant cell model |
| title_short | p53-Independent checkpoint controls in a plant cell model |
| title_sort | p53 independent checkpoint controls in a plant cell model |
| topic | Checkpoint adaptation Hydroxyurea S and G2 checkpoints p53-independent checkpoints Allium cepa L. meristems |
| url | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300009 |
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