Name: recombinant dna in cloning and gmos
Uploaded: 2026-08-26T08:20:51.528Z
Duration: 1 min 34 s
Channel: JoVE

Rekombinante DNA ist DNA aus verschiedenen Quellen, normalerweise verschiedene Spezies, die im Labor f&#xFC;r weitverbreitete Anwendungen in der klinischen und wissenschaftlichen Forschung kombiniert werden.
 Rekombinante DNA besteht normalerweise aus einem Gen von Interesse, hier Insulin von einem Spenderorganismus, welches in einen Vektor inseriert ist, selbstreplizierende DNA von einem anderen Organismus, wie einem Virus oder einem Plasmid, einem kleinen kreisf&#xF6;rmigen St&#xFC;ck bakterieller DNA.
 Die DNA von jeder Quelle wird zuerst durch Restriktionsendonukleasen geschnitten, Enzyme, die DNA an einer bestimmten Sequenz spalten.
 Die Spender-DNA wird mit Hilfe des Enzyms DNA-Ligase an die Enden der Vektor-DNA gebunden.
 Die rekombinante DNA wird dann in einen Wirtsorganismus, ein Bakterium oder eine Hefe, inseriert, wo sie repliziert wird, wodurch viele Kopien des interessierenden Gens erzeugt werden.
 Das Gen kann dann leichter untersucht oder, wie im Fall von Insulin, unter Verwendung der Zellmaschinerie des Wirts in Protein &#xFC;bersetzt werden.

Khan, Suliman, Muhammad Wajid Ullah, Rabeea Siddique, Ghulam Nabi, Sehrish Manan, Muhammad Yousaf und Hongwei Hou. 2016. "Die Rolle der rekombinanten DNA-Technologie zur Verbesserung des Lebens." Internationales Journal für Genomik 2016. [<a href="https://doi.org/10.1155/2016/2405954" target="__blank">Quelle</a>]

Matsumura, Ichiro. 2015. "Warum Johnny nicht klonen kann: Häufige Fallstricke und nicht so häufige Lösungen." BioTechniques 59 (3): IV–XIII. [<a href="https://doi.org/10.2144/000114324" target="__blank">Quelle</a>]

rekombinante dna

Recombinant DNA Technology

<h4>&#xDC;berblick</h4>
 
 Wissenschaftler stellen rekombinante DNA durch das Verbinden von DNA-St&#xFC;cken von verschiedenen Quellen, meist verschiedenen Arten, im Labor her. Die DNA Klonierung erm&#xF6;glicht den Forschern bestimmte Gene zu untersuchen, durch die Insertion in leicht manipulierbare Zellen, wie Bakterien. Organismen, die rekombinante DNA enthalten, sind als genetische ver&#xE4;nderte Organismen (GVO) bekannt. Die rekombinante DNA-Technologie f&#xFC;hrt zu Organismen mit neuen Genen, die in der Wissenschaft, der Medizin, und der Landwirtschaft n&#xFC;tzlich sein k&#xF6;nnen.
 
 <h4>Wie stellen Wissenschaftler rekombinante DNA her?</h4>
 
 Bei der Herstellung von rekombinanter DNA wird das gew&#xFC;nschte Gen in einen Vektor eingef&#xFC;gt. Der Vektor ist ein Vehikel, der den Transport von fremder DNA in die Wirtszellen zur DNA-Replikation und Proteinexpression erm&#xF6;glicht. Am meisten werden Plasmide als Klonierungsvektoren verwendet. Das sind kleine zirkulare DNA-St&#xFC;cke, die sich unabh&#xE4;ngig von der chromosomalen Wirts-DNA replizieren.
 
 Um rekombinante DNA herzustellen, m&#xFC;ssen die DNA, die das gew&#xFC;nschte Gen enth&#xE4;lt und der Vektor mit Restriktionsenzyme an einer bestimmten Nukleotid-Sequenz, der Restriktionsschnittstelle, geschnitten werden. Ein Enzyme, die DNA-Ligase, ligiert dann das Zucker-Phosphate-Grundger&#xFC;st, wo sich des gew&#xFC;nschte Gen und das Plasmid verbinden.
 
 Das Ergebnis ist dann ein rekombinantes DNA-Molek&#xFC;l, das aus einem Vektor mit einem integrierten neuen DNA-St&#xFC;ck, einem Insert, besteht. Ein Wissenschaftler kann dann diesen DNA-Hybrid in einen neuen Wirtsorganismus einf&#xFC;hren, normalerweise Bakterien, wo es einfach und schnell vervielf&#xE4;ltigt wird. Dadurch entstehen viele Kopien des gew&#xFC;nschten Gens, was notwendig f&#xFC;r die wissenschaftliche Forschung und andere Anwendungen ist. Das Gen kann dann auch in der Wirtszelle transkribiert und &#xFC;bersetzt werden wobei das gew&#xFC;nschte Protein produzieret wird, wie zum Beispiel Insulin.
 
 Die Herstellung von rekombinanter DNA ist kein perfekter Prozess, da viele Fehler passieren. Zum Beispiel, der Vektor kann sich auch ohne das Insert schlie&#xDF;en oder das Insert wurde verkehrt verbunden (umgekehrt). Daher m&#xFC;ssen die Wissenschaftler bevor sie die DNA nutzen, sie auf Richtigkeit &#xFC;berpr&#xFC;fen. 
 Die Sequenzierung der Nukleotide kann dabei helfen die Bakterienkolonien zu identifizieren, die das Plasmid mit dem richtigen Insert haben.
 
 Wissenschaftler nutzen rekombinante DNA um Gene und Proteine zu untersuchen
 
 Die rekombinante DNA-Technologe ist besonders n&#xFC;tzlich wenn ein Forscher viele Kopien eines gew&#xFC;nschten Gens oder Proteins ben&#xF6;tigt. Es ist jedoch m&#xF6;glich, dass die Forschung des Wissenschaftlers komplexer ist, und die Reinigung oder die Detektion des Proteins ben&#xF6;tigt. Um dies zu erm&#xF6;glichen kann der Forscher einen Protein-tag oder Reporter an das gew&#xFC;nschte Protein f&#xFC;gen. Das sind Proteine die genutzt werden, um das Genprodukt zu lokalisieren. Dabei entsteht ein Fusionsgen oder ein chim&#xE4;risches Gen.
 
 <h4>Die Anwendung in der Medizin und Landwirtschaft</h4>
 
 Wissenschaftler haben die rekombinante DNA-Technologie als erstes f&#xFC;r die Produktion von menschlichem Insulin aus Bakterien genutzt, wodurch eine Therapie f&#xFC;r Diabetes entstand. Seit dieser ersten Entdeckung haben Wissenschaftler verschiedene andere rekombinante DNAs f&#xFC;r therapeutische Zwecke entwickelt. Rekombinante Bakterien produzieren das menschliche Wachstumshormon, Somatropin, welches ein Protein ist, dass f&#xFC;r das normale Wachstum und Entwicklung ben&#xF6;tigt wird. Es wird genutzt, um Patienten mit einem Mangel des Wachstumshormons zu behandeln. Rekombinante S&#xE4;ugetierzellen, die von Menschen und Hamstern stammen, produzieren den Faktor VIII. Dies ist ein Protein, das f&#xFC;r die normale Blutgerinnung zur Behandlung von Patienten mit H&#xE4;mophilie ben&#xF6;tigt wird. Offensichtlich ist die rekombinante DNA-Technologie ein leistungsstarkes Werkzeug f&#xFC;r die Produktion essenzieller Proteine in gro&#xDF;em Ma&#xDF;stab.
 
 Landwirtschaftliche Fortschritte in der rekombinanten DNA-Technologie wirken sich auch auf das menschliche Wohlergehen aus. So erlitten Maisbauern fr&#xFC;her beispielsweise erhebliche Erntesch&#xE4;den durch den Maisz&#xFC;nsler, einen Sch&#xE4;dling. Als Reaktion darauf isolierten Wissenschaftler Gene aus einem bodenbewohnenden Bakterium, demBacillus thuringiensis (Bt), um genetisch ver&#xE4;nderten, sch&#xE4;dlingsresistenten Mais zu erzeugen. Bacillus thuringiensis produziert auf nat&#xFC;rliche Weise Proteine, die f&#xFC;r bestimmte Insekten, aber nicht f&#xFC;r Menschen, Pflanzen oder andere Tiere giftig sind. Die Einf&#xFC;hrung von sch&#xE4;dlingsresistentem Bt-Mais verbesserte die Ernteertr&#xE4;ge und verringerte den Einsatz von chemischen Pestiziden. Solche landwirtschaftlichen Anwendungen der DNA-Technologie k&#xF6;nnen die Qualit&#xE4;t und Quantit&#xE4;t der globalen Nahrungsmittelversorgung verbessern.

Rekombinante DNA

Overview

Scientists create recombinant DNA by combining DNA from different sources&#x2014;often, other species&#x2014;in the laboratory. DNA cloning allows ...

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recombinant dna in cloning and gmos

Recombinant DNA is made by joining DNA from different sources in the lab. Scientists often use it to clone genes and study them in cells that are easy to handle, such as bacteria. Organisms that carry recombinant DNA are called genetically modified organisms, or GMOs. This technology gives scientists new tools for research, medicine, and agriculture.

To build recombinant DNA, researchers place a gene of interest into a vector, which is a DNA carrier that moves foreign DNA into a host cell. The most common vectors are plasmids, small circular DNA molecules that copy themselves separately from the cell’s chromosomal DNA. Scientists cut both the donor DNA and the vector at specific restriction sites using restriction enzymes. Then DNA ligase seals the sugar-phosphate backbone where the insert joins the plasmid.

The final product is a recombinant DNA molecule with a vector carrying an inserted piece of donor DNA. Scientists can put this hybrid DNA into a host organism, usually bacteria or yeast. The host then replicates the DNA quickly, making many copies of the gene of interest. In some cases, the host’s machinery also transcribes and translates the gene into a protein, such as human insulin.

Creating recombinant DNA is not always perfect. The vector may close without taking in the insert, or the insert may end up in the wrong direction. Before moving on, researchers check for these errors. Nucleotide sequencing helps them find bacteria colonies that contain plasmids with the correct insert.

Recombinant DNA is useful when scientists need many copies of a gene or a protein product. Some projects need extra steps, such as making the protein easier to detect or purify. For that reason, researchers may attach a tag or reporter protein to create a fusion gene, also called a chimeric gene.

This technology has major uses in medicine and agriculture. Scientists first used recombinant DNA to make human insulin in bacteria for diabetes treatment. They also use recombinant bacteria to produce human growth hormone for growth hormone deficiency. Recombinant mammalian cells, from humans and hamsters, make Factor VIII to treat hemophilia. In agriculture, scientists used genes from Bacillus thuringiensis, or Bt, to create pest-resistant corn. Bt proteins are toxic to certain insects, not humans, plants, or other animals, so Bt corn can improve crop yields and reduce chemical pesticide use.

Recombinant DNA in Cloning and GMOs

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key terms and concepts

See how scientists build recombinant DNA with plasmids, restriction enzymes, and ligase, then use it to make proteins and GMOs in medicine and farming.

Recombinant DNA in Cloning and GMOs | JoVE K12

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Recombinant DNA in Cloning and GMOs

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