Transient gene expression

Low levels of expression or transient gene expression. Laigely because the DNA sequence is inserted randomly into the host s DNA, the regulatory sequences necessary for full and stable expression are at least partially lacking, leading to under-expression or transient expression. 

Baldi, L., Muller, N., Picasso, S., Jacquet, R., Girard, P., Thanh, H. R, et al. (2005). Transient gene expression in suspension HEK-293 cells application to large-scale protein production. Biotechnol. Prog. 21,148-153. 

C. Systemic administration of adenoviral vectors has not been used in the treatment of hemophilia because of the transient gene expression and immunogenic consequences of adenoviral delivery. All of the other approaches are under investigation or have been published in the literature on treatment of hemophilia. 

Heifetz, 2000). Although protoplasts that have been transformed in this way have been shown to exhibit transient gene expression, stable plastid transformation has not yet been successfully achieved (Knoblauch et al., 1999). 

Delivery of expression plasmids to various tissues or solid tumors results in transient gene expression with a fast decline in expression levels (Doh et al., 1997 Aihara and Miyazaki, 1998). Therefore, it is important to develop strategies to substantially increase the persistence of gene expression in transfected tissues. 

Wurm FM, Bernard A (2001), Transient gene expression from mammalian cells a new chapter in animal cell technology, Cytotechnology 35 155-156. 

Lang J. (1995b) Application of human growth hormone transient gene expression system in insulin secreting cells. In Breakthrough Newsletter 3 4-5. 

Selden RF, Howie KB, Rowe ME, et al. (1986) Human growth hormone as a reporter gene in regulation studies employing transient gene expression. In Mol. Cell Biol. 6 3173-79. 

Hong K, Sherley J, Lauffenburger DA. Methylation of episomal plasmids as a barrier to transient gene expression via a synthetic delivery vector. Biomol Eng... 

Kapila, J. De Rycke, R. van Montagu, M. Angenon, G. Agrobacterium mediated transient gene expression system for intact leaves. Plant Sci. 1996, 122, 101-108. 

Plasmids do not integrate into the genome of the host cell, thus being unqualified for stable transfection and long-term expression of therapeutic protein, but are suited for all applications requiring transient gene expression [22]. 

Fourth, MIDGE vectors exhibit a feasible expression of recombinant proteins in mammalian cells. Compared to plasmids, expression rates are equal or even higher (depending on the promoter employed, the transfection method and the cell line used), probably due to their small size. A high level of transient gene expression is achieved for several hours or days, and a lower level of expression can be detected for several weeks (for up to 80 days after intramuscular injection). 

Meissner, P., Kulangara, A., Pick, H., Chatel-lard, P. and Wurm, F.M. (2001) Transient Gene Expression Recombinant Protein Production with Suspension-Adapted HEK-293EBNA Cells. Biotechnol. Bioeng. 75, 2 197-203. 

To test these models, we determined whether transcription initiated in the vicinity of exon 5 1 or 5 2, using primer extension, and moreover, assayed directly whether functional promoters resided in the 5 flanking regions of either of these exons. This latter test involved construction of appropriate expression vectors, followed by assay for transient gene expression. 

Transient gene expression assays were performed to test whether a functional promoter resided in the 5 -flanking region of exon 5 2. Putative... 

If one cannot include I-Scel in the strategy for making a transgenic, the DNA should be linearized or the insert should be isolated from the plasmid sequences. Supercoiled DNA, however, can be used for transient gene expression work. After phenol-chloroform extraction to remove the restriction enzyme, the DNA is further purified on a MicroSpin column (MicroSpin S-300HR, Amersham Biosciences, Piscataway, NJ) as follows ... 

Electroporation-Mediated DNA Transfer to Tobacco Protoplasts for Transient Gene Expression Assays... 

Lindsey, K., and Jones, M. G. K. (1987) Transient gene expression in electroporated protoplasts and intact cells of sugar beet. Plant Mol. Biol. 10, 43-52. 

A major drawback of current transfection vectors is that they have poor in vivo transfection efficiency and only confer transient gene expression. Indeed, poor transfection efficiency is due, in part, to the lack of stability of the non-viral vector-DNA complex under physiological conditions and its ability to interact with blood plasma proteins after intravenous injection, the extracellular matrix, and undesirable cells, and its possible degradation by enzymes, even before reaching the intracellular compartment (Scheme 12). In order to overcome these problems and to enable the carrier to translocate across cellular membranes (thus... 

Transient gene expression frequency at the cellular level can be used to evaluate apparatus efficiency. 

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