Genetically modified food and other kinds of genetical engineering

Textbooks define "genetic engineering" as "the application of in vitro procedures for the manipulation, recombination, and expression of DNA and the development of genetically modified organisms."

The discovery of restriction enzymes (or restriction endonucleases) was an important development in genetic engineering. Restriction enzymes can be found in bacteria and serve as a defense mechanism (e.g. against viruses). What is distinctive about them is that they can discern specific base sequences (so-called recognition sites) and cleave them. As such they are a kind of natural "gene scissors". Restriction enzymes have been bioengineered to improve their efficiency, which led to the development of the modern techniques of genome editing. The most famous genome editing technique is the CRISPR/Cas9 technique (see also the module Genome editing).

Restriction enzymes play an important role in cloning (the replication of DNA sequences). This biotechnological method involves so-called vectors that serve as a vehicle to insert specific DNA sequences (e.g. genes) into an organism (mostly bacteria). Frequently used vectors are plasmids, i.e. DNA molecules that can be found in bacteria but are independent of chromosomal DNA. Now, restriction enzymes cut both the plasmids and the DNA sequence at the respective recognition site. Then, the cut DNA sequence is inserted into the plasmid. Finally, the resultant recombinant plasmid is introduced into the bacterium, in which it replicates.

Since the chemical structure of DNA is nearly identical in all living organisms, genes are transferable between different species. An organism that has been inserted genes from another organism is called a transgenic organism. An example particularly relevant in pharmaceutics and medicine is insulin, which is extracted from bacteria with the method described above.

Brown, T.A. (2016): Gene Cloning & DNA Analysis. 7. edition. Oxford: Wiley-Blackwell.

Madigan, Michael T. / Martinko, John M. / Stahl, David A. / Clark, David P. (2013): Brock Mikrobiologie. 13., aktualisierte Auflage. München: Pearson Higher Education 422-449.

Information on genetic engineering provided by the Federal Ministry of Food and Agriculture Online Version

Especially in the political debate, colour designations are used to identify the various fields of application of genetic engineering. These classifications are in turn based on the colour categorisation of the different areas of biotechnology, to which genetic engineering is assigned as a field.

For further information on the colour categorisation of the different areas of biotechnology see:

Gottwald, F.-T. / Krätzer, A. (2014): Irrweg Bioökonomie. Kritik an einem totalitären Ansatz. Berlin: Suhrkamp, 27–40.

APA-Science (2013): Die Farben der Biotechnologie. Online Version (German)

Barcelos, M. C. S. / Lupki, F. B. / Campolina, G. A. / Nelson, D. L. / Molina, G. (2018): The colors of biotechnology: general overview and developement of white, green and blue areas. In: FEMS Microbiology Letters 365 (21). Online Version

Kafarski, P. (2012): Rainbow code of biotechnology. In: Chemik 66 (8), 811–816. Online Version

The following labels are in common use:

Green: agriculture
red: medical and pharmaceutical applications
white and grey: environmental technology and ecology
blue: marine biology
brown: wastewater treatment
yellow: natural resource modification

A concise overview of the colour subdivision of the different areas of application of genetic engineering can be found here:

Wissenschaftliche Dienste des Deutschen Bundestages (2005): Grüne, Rote, Weiße und Graue Gentechnik. Der aktuelle Begriff Nr. 18/05. Verf. v. C. Steinhoff. Online Version (German)

Genetically modified foods fall under the use of genetic engineering methods in nutritional and agricultural applications and therefore are to be labeled „green“.

A comprehensive overview of this topic is offered by the 13th DRZE expert report "Gentechnik in der Lebensmittelproduktion". This volume presents the scientific, legal and ethical problems arising from the use of genetic engineering in food producion.

Sturma, D. / Lanzerath, D. / Heinrich, B. (eds.) (2011): Gentechnik in der Lebensmittelproduktion. Naturwissenschaftliche, rechtliche und ethische Aspekte. Ethik in den Biowissenschaften – Sachstandsberichte des DRZE Bd. 13. Freiburg i. Br.: Karl Alber. 

Further introductory literature

Hellsten, S.K. (2016): Genetic Modification (GMOs): Food. In: ten Have, H. (ed.) Encyclopedia of Global Bioethics. Cham: Springer. Online Version

Singh, S. / Kaur, R. (2022): Genetically Modified Food (GMF) and its challenges. In: Kumar, A. / Patruni, K. / Singh, V. (ed.): Recent Advances in Food Biotechnology. Singapur: Springer. Online Version

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