Nuclear matrix attachment regions and transgene expression in plants

Matrix attachment regions (MARs) are operationally defined as DNA elements that bind specifically to the nuclear matrix in vitro. It is possible, although unproven, that they also mediate binding of chromatin to the nuclear matrix in vivo and alter the topology of the genome in interphase nuclei. When MARs are positioned on both sides of a transgene their presence usually results in higher and more stable expression in transgenic plants or cell lines, most likely by minimizing gene silencing. This paper reviews the research progress of MARs and believes that the exploitation of MARs may be an important strategy for stabilising transgene expression levels in genetically engineered cereals.Key words: matrix attachment region; transgene; gene expression; gene regulation