Linked Life Data

12785094

Source:http://linkedlifedata.com/resource/pubmed/id/12785094

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5-6
pubmed:dateCreated
2003-6-5
pubmed:abstractText
We review micromechanical experiments on mitotic chromosomes. We focus on work where chromosomes were extracted from prometaphase amphibian cells, and then studied by micromanipulation and microfluidic biochemical techniques. These experiments reveal that chromosomes have well-behaved elastic response over a fivefold range of stretching, with an elastic modulus similar to that of a loosely tethered polymer network. Perturbation by microfluidic 'spraying' of various ions reveals that the mitotic chromosome can be rapidly and reversibly decondensed or overcondensed, i.e. that the native state is not maximally compacted. Finally, we discuss microspraying experiments of DNA-cutting enzymes which reveal that the element which gives mitotic chromosomes their mechanical integrity is DNA itself. These experiments indicate that chromatin-condensing proteins are not organized into a mechanically contiguous 'scaffold', but instead that the mitotic chromosome is best thought of as a cross-linked network of chromatin. Preliminary results from restriction-enzyme digestion experiments indicate a spacing between chromatin 'cross-links' of roughly 15 kb, a size similar to that inferred from classical chromatin-loop-isolation studies. We compare our results to similar experiments done by Houchmandzadeh and Dimitrov (J Cell Biol 145: 215-213 (1999)) on chromatids reconstituted using Xenopus egg extracts. Remarkably, while the stretching elastic response of the reconstituted chromosomes is similar to that observed for chromosomes from cells, the reconstituted chromosomes are far more easily bent. This result suggests that reconstituted chromatids have a large-scale structure which is quite different from chromosomes in somatic cells. More generally our results suggest a strategy for the use of micromanipulation methods for the study of chromosome structure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0142-4319
pubmed:author
pubmed:issnType
Print
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
409-31
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Micromechanical studies of mitotic chromosomes.
pubmed:affiliation
Department of Physics, University of Illinois at Chicago, 845 West Taylor Street, Chicago, IL 60607-7059, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Review, Research Support, Non-U.S. Gov't