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 the chromatin within the nucleus. These elements constitute anchor points of the DNA for the chromatin scaffold and serve to organize the chromatin into structural domains. Studies on individual genes led to the conclusion that the dynamic and complex organization of the chromatin mediated by S/MAR elements plays an important role in the regulation of gene expression.

Recently, Tetko has found a strong correlation of intragenic S/MARs with spatiotemporal expression of genes in Arabidopsis thaliana. 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.