Gene constructs

The choice between constitutive promoters (such as the CaMV 35S or maize ubiquitin-1 promoters) and tissue-specific promoters needs to be evaluated on an empirical basis, hi our experience, seed-specific promoters are beneficial in some plants (e.g. peas) while constitutive promoters appear to generate better results in cereals (rice and wheat). It is important to get high-level antibody 

The T-DNA (transferred DNA) region of the Ti plasmid carries the genes which are transferred to, integrated, and expressed in recipient plant cells. T-DNA from pTi contains genes which promote the synthesis of auxins, C3rtokinins 

A typical binaiy vector is small (c. 10 kb) to facilitate genetic manipulation and transformation. The basic components of a binaiy vector are shown in Hgure 1. They are  

Supplementary features of some binary vectors include overdrive and T-DNA transfer stimulator sequences (to improve T-strand synthesis), and a cos region from lambda bacteriophage to allow maintenance of cosmid-based plant genomic libraries in AgrobacTeriutn (51 and refs contained therein). 

Rgine 1 Scbematic of a typical binary vector for Agrobacterium-mediated transformation. 

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In the biosynthetic approach, protein expression in E. coli [27], yeast [28, 29], and plants [30, 31] have been employed. This approach requires the construction of genes encoding for these repetitive polypeptides. Different methods for gene construction have been pubhshed multimerization [32], recursive directional ligation [33], and recursive directional ligation via plasmid reconstruction [23, 34]. 

REPORTER GENE CONSTRUCTS WITH VARIABLE AMOUNTS OF 5 -FLANKING DNA... 

Figure 39-11. Location of hormone response elements (HREs) A, B, and C using the reporter gene-transfection approach. A family of reporter genes, constructed as described in Figure 39-10, can be transfected individually into a recipient cell. By analyzing when certain hormone responses are lost in comparison to the 5 deletion, specific hormone-responsive elements can be located.

After transfecting the mutated gene construct into the ES cells, an occasional rare homologous recombi-... 

A replication-deficient adenovirus has been used to deliver a gene construct, which contains within its promoter region a radiation-responsive element. Upon irradiation with conventional doses of X rays, this construct initiates transcription of the gene coding for the toxic cytokine, tumor necrosis factor-a (35). The above is an exquisite example of how emerging delivery and gene therapies are fast blurring the distinction between an active and an excipient (Fig. 3D). 

The gene constructs used are synthetic constructs. The introduction of pure DNA would lead to its rejection by the receiving organism. The production of synthetic constructs is needed to have any effect. Whether they work or not is tested in a trial and error process. 

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