Journal article
Matrix attachment regions (MARs) enhance transformation frequencies and reduce variance of transgene expression in barley
Nuclear matrix attachment regions (MARs) are defined as genomic DNA sequences, located at the physical boundaries of chromatin loops. They are suggested to play a role in the cis unfolding and folding of the chromatin fibre associated with the regulation of gene transcription. Inclusion of MARs in transgene cassettes enhances their expression and reduces position-effect variations in the transgenic host.
The present study is the first to investigate the influence of MAR sequences on transformation frequencies and transgene expression in barley, which is highly relevant to the future improvement of this crop by biotechnology. Two plant MAR sequences were tested both for their ability to bind to the nuclear matrix of barley leaf nuclei and to regulate the expression of a reporter gene in transgenic barley.
Competitive in vitro MAR binding assays with the 520 bp P1-MAR from soybean and the 516 bp TBS-MAR from petunia revealed that only the P1-MAR had specific binding affinity for barley nuclear matrices. The barley transformation frequency with the uidA reporter gene was increased 2-fold when the gene was flanked with either the P1-MAR or TBS-MAR, while the gene copy number was strongly reduced.
The presence of P1-MAR sequences increased the mean activity and reduced the variance in expression of a co-integrated reporter gene in barley consistent with the proposed model of MAR activity.
Language: | English |
---|---|
Publisher: | Kluwer Academic Publishers |
Year: | 2002 |
Pages: | 45-58 |
Journal subtitle: | An International Journal on Molecular Biology, Molecular Genetics and Biochemistry |
ISSN: | 01674412 and 15735028 |
Types: | Journal article |
DOI: | 10.1023/A:1014464127973 |
Biochemistry, general Cells, Cultured Gene Expression Regulation Glucuronidase Glycine max Hordeum Life Sciences MAR Nuclear Matrix Plant Pathology Plant Sciences Plants, Genetically Modified Plasmids Protein Binding Recombinant Fusion Proteins Solanaceae Transformation, Genetic barley nuclear matrix transgene expression