Minimizing the unpredictability of transgene expression in plants: the role of genetic insulators

Plant Cell Rep. 2012 Jan;31(1):13-25. doi: 10.1007/s00299-011-1167-y. Epub 2011 Oct 11.

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 often highly variable amongst independent transgenic lines. Two of the major contributing factors to this type of inconsistency are inappropriate enhancer-promoter interactions and chromosomal position effects, which frequently 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 the genetic engineering of these organisms. In this review, we discuss strategies for improving foreign gene expression in 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, recent studies regarding their use in genetically engineered plants indicate that they hold great promise for the improvement of transgene expression, and thus the future of plant biotechnology.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Chromosomes, Plant
  • Enhancer Elements, Genetic
  • Gene Expression Regulation, Plant*
  • Heterochromatin / genetics
  • Insulator Elements*
  • Plants, Genetically Modified / genetics*
  • Promoter Regions, Genetic
  • Transgenes

Substances

  • Heterochromatin