- Matrix attachment region
Matrix attachment region (MAR), also known as Scaffold/matrix attachment regions (S/MARs), are sequences in the DNA of eukaryotic chromosomes where the
nuclear matrix attaches. S/MARs mediate structural organization of thechromatin within the nucleus. These elements constitute anchor points of theDNA for thechromatin scaffold and serve to organize thechromatin into structural domains. Studies on individual genes led to the conclusion that the dynamic and complex organization of thechromatin mediated by S/MAR elements plays an important role in the regulation ofgene expression .Recently, Tetko has found a strong correlation of intragenic S/MARs with spatiotemporal expression of genes in "
Arabidopsis thaliana ". [See Tetko, Igor V., Georg Haberer, Stephen Rudd, Blake Meyers, Hans-Werner Mewes, and Klaus F. X. Mayer (2006) Spatiotemporal Expression Control Correlates with Intragenic Scaffold Matrix Attachment Regions (S/MARs) in "Arabidopsis thaliana". PLoS Computational Biology 2:136-145. [http://compbiol.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pcbi.0020021 Online copy] .] On a genome scale, pronounced tissue- and organ-specific and developmental expression patterns of S/MAR-containing genes have been detected. Notably,transcription factor genes contain a significant higher portion of S/MARs. The pronounced difference in expression characteristics of S/MAR-containing genes emphasizes their functional importance and the importance of structural chromosomal characteristics for gene regulation in plants as well as within other eukaryotes.Notes
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