Transgene Integration: Use of Matrix Attachment Regions

Matrix attachment regions (MARs) are operationally defined as DNA elements that bind specifically to the nuclear matrix in vitro. When MARs are positioned at the 5′- and 3′-ends of a transgene higher more predictable expression of the transgene results. MARs are increasingly being applied to prevent unwanted transgene silencing, which is especially common when direct DNA transformation methods are used. This chapter describes methods for the isolation of MARs and the subsequent methods allowing the investigator to incorporate MARS into transformation strategies that can both improve transformation frequency and result in predictable, stable expression of the transgenic trait.