Linked Life Data

11290584

Source:http://linkedlifedata.com/resource/pubmed/id/11290584

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2001-4-6
pubmed:abstractText
During differentiation, megakaryocytes increase ploidy through a process called endomitosis, whose mechanisms remain unknown. As it corresponds to abortive mitosis at anaphase and is associated with a multipolar spindle, investigation of chromosome segregation may help to better understand this cell-cycle abnormality. To examine this variation, a new method was developed to combine primed in situ labeling to label centromeres of one chromosome category and immunostaining of tubulin. Human megakaryocytes were obtained from normal bone marrow culture. By confocal microscopy, this study demonstrates an asymmetrical distribution of chromosomes (1 or 7) either between the spindle poles at anaphase stage of endomitosis and between the different lobes of interphase megakaryocyte nuclei. The metaphase/anaphase checkpoint appears normal on the evidence that under nocodazole treatment megakaryocytes progressively accumulate in pseudo-metaphase, without spontaneous escape from this blockage. Immunostaining of p55CDC/hCDC20 with similar kinetochore localization and dynamics as during normal mitosis confirms this result. HCdh1 was also expressed in megakaryocytes, and its main target, cyclin B1, was normally degraded at anaphase, suggesting that the hCdh1-anaphase-promoting complex checkpoint was also functional. This study found the explanation for these unexpected results of an asymmetrical segregation coupled to normal checkpoints by careful analysis of multipolar endomitotic spindles: whereas each aster is connected to more than one other aster, one chromosome may segregate symmetrically between 2 spindle poles and still show asymmetrical segregation when the entire complex spindle is considered.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
97
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2238-47
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:11290584-Anaphase, pubmed-meshheading:11290584-Cell Cycle Proteins, pubmed-meshheading:11290584-Cells, Cultured, pubmed-meshheading:11290584-Chromosomes, Human, pubmed-meshheading:11290584-Cyclin B, pubmed-meshheading:11290584-Cyclin B1, pubmed-meshheading:11290584-Fluorescent Antibody Technique, Indirect, pubmed-meshheading:11290584-Hematopoietic Stem Cells, pubmed-meshheading:11290584-Humans, pubmed-meshheading:11290584-Image Processing, Computer-Assisted, pubmed-meshheading:11290584-In Situ Hybridization, Fluorescence, pubmed-meshheading:11290584-Megakaryocytes, pubmed-meshheading:11290584-Metaphase, pubmed-meshheading:11290584-Microscopy, Confocal, pubmed-meshheading:11290584-Mitosis, pubmed-meshheading:11290584-Mitotic Spindle Apparatus, pubmed-meshheading:11290584-Nocodazole, pubmed-meshheading:11290584-Polyploidy, pubmed-meshheading:11290584-Proteins, pubmed-meshheading:11290584-Thrombopoietin
pubmed:year
2001
pubmed:articleTitle
Asymmetrical segregation of chromosomes with a normal metaphase/anaphase checkpoint in polyploid megakaryocytes.
pubmed:affiliation
Institut National de la Santé et de la Recherche Médicale (INSERM) U362, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't