Submitted to: Plant Cell Reports
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/27/2011
Publication Date: 1/15/2012
Citation: Singer, S., Liu, Z., Cox, K.D. 2012. Minimizing the unpredictability of transgene expression in plants: the role of genetic insulators. Plant Cell Reports. 31:13-25. Interpretive Summary: The enhancer-promoter cross-talk within a composite transgene can interfere with tissue-specific expression of the introduced promoters in transgenic plants. Therefore, a new insulation strategy or system is needed. In this paper, we review and discuss a few of the strategies for the use of genetic insulator elements for prevention of enhancer-promoter or promoter-promoter cross-talk in tansgenic plants.
Technical Abstract: The genetic transformation of plants has become a necessary tool for fundamental plant biology research, as well as the generation of engineered plants exhibiting improved agronomic and industrial traits. However, this technology is significantly hindered by the fact that transgene expression is highly variable, as well as unpredictable, between independent transgenic lines. Two of the major contributing factors to this variability are inappropriate enhancer-promoter interactions and chromosomal position effects, which often result in mis-expression or silencing of the transgene, respectively. Since the precise, often tissue-specific, expression of the transgene(s) of interest is often a necessity for the successful generation of transgenic plants, these undesirable side effects have the potential to pose a major challenge for plant biotechnology. In this review, we discuss strategies for improving foreign gene expression in transgenic plants via the inclusion of enhancer-blocking insulators, which function to impede enhancer-promoter communication, and barrier insulators, which block the spread of heterochromatin, in transgenic constructs. While a complete understanding of these elements remains elusive, the results accumulated regarding their use in transgenic plants over recent years indicates that they hold great promise for the improvement of transgene expression in plant biotechnology in the future.