Biotechnology (continued)
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Microbiology
Genetic transformation normally is achieved easily with
microorganisms; new genetic material may be inserted into
them, either into their chromosomes or into extrachromosomal
elements (plasmids) [Fig. 3]. Thus, bacteria and yeast can be
created to metabolize specific products or to produce new
products. Concomitant technologies have been developed to
scale up the production of the microorganisms to generate
products (for example, enzymes, carbohydrates, and proteins)
in great quantity.
Fig. 2: Examples of biotechnological DNA and gene targeting applications. DNA recognition domains (in this case for TAL effectors) can be fused to DNA-cleaving enzymes such as FokI to
create double-strand breaks at desired locations in a genome. Making such breaks in the DNA allows researchers to disrupt genes, insert new DNA, or edit existing DNA sequences at those
locations for basic biotechnology or medical purposes. TAL effectors with their own activation domain (AD) can be similarly customized to drive expression of genes of interest in different
organisms. Similarly, the AD can be replaced with a repressor domain (RD) to create targeted off-switches for genes. (Credit: Adam J. Bogdanove, Erin L. Doyle, and Katherine E. Wilkins)
Fig. 3: The biotechnological Agrobacterium vector method. The Ti plasmid of the plant bacterium
Agrobacterium tumefaciens is used in plant genetic engineering. (Credit: P. H. Raven and G. B.
Johnson; copyright © McGraw-Hill Education)
