Describe techniques and applications used in recombinant DNA technology

Describe techniques and applications used in recombinant DNA technology, for example:

  • the development of transgenic organisms in agricultural and medical applications (ACSBL087)
  • Construction of Genomic Library:
    • Collection of total genomic DNA of a single organism.
    • Each fragment of DNA is stored in a vector (organisms that act as carriers of DNA other than their own DNA to another host and have the capability of being expressed in the host) and innumerable vectors each having a distinct fragment of DNA makes up the gene library.
    • The DNA used to construct the gene library are termed as cDNA, a type of DNA that has been obtained from a single stranded mRNA strand by a process called reverse transcription (the process in which DNA is created from RNA) with the help of a special type of enzyme called reverse transcriptase.
    • At first, a cDNA library is formed and then, segments from this cDNA are cleaved by endonucleases and the cleaved sections are joined with vector DNA by DNA Ligase.
    • Applications:
      • First step in any DNA sequencing projects.
      • Helps in identification of the novel pharmaceutically important genes.
      • Helps in identification of new genes which were silent in the host.
      • It helps us in understanding the complexity of genomes.
      • Serving as a source of genomic sequence for generation of transgenic animals through genetic engineering.
      • Study of the function of regulatory sequences in vitro.
      • Study of genetic mutations in cancer tissues.
      • Create cDNA libraries to determine what genes are being expressed at a particular time.
  • Gene Cloning:
    • Process in which identical copies of a gene are produced.
    • The gene which will be “xeroxed” is termed as the “gene of interest”.
    • At first the gene of interest is selected and is separated from the DNA strand by using restriction endonuclease, an enzyme that cuts DNA at specific sites.
    • Next, a vector is selected that will carry the gene of interest is selected. Plasmid, the extracellular DNA present in the vector contains a target site, a site where the gene of interest will be inserted. The target site in the plasmid is also digested by restriction enzyme.
    • The gene of interest is introduced in the vector and joined with the target site by DNA ligase.
    • The vector containing the gene of interest is placed in an environment suitable for multiplication. We will obtain the targeted protein after the vector starts multiplying. Along with the protein, some chemical materials of the vector will also be present thus, the protein needs to be purified.
    • Applications:
      • DNA cloning can be used to make human proteins with biomedical applications, such as the insulin.
      • Other examples of recombinant proteins include human growth hormone, which is given to patients who are unable to synthesize the hormone, and tissue plasminogen activator (tPA), which is used to treat strokes and prevent blood clots.
      • In basic research labs, biologists often use DNA cloning to build artificial, recombinant versions of genes that help them understand how normal genes in an organism function.
      • Once characterized and manipulated to provide signals for appropriate expression, cloned genes may be inserted into organisms, generating transgenic organisms, also termed genetically modified organisms (GMOs). Although most GMOs are generated for purposes of basic biological research (see for example, transgenic mouse), a number of GMOs have been developed for commercial use, ranging from animals and plants that produce pharmaceuticals or other compounds (pharming), herbicide-resistant crop plants, and fluorescent tropical fish (GloFish) for home entertainment.

 

Extract from HSC Biology Stage 6 Syllabus. © 2017 Board of Studies NSW.

EasyBio > Genetic Change > Genetic Technologies > Describe techniques and applications used in recombinant DNA technology

Describe techniques and applications used in recombinant DNA technology, for example:

  • the development of transgenic organisms in agricultural and medical applications (ACSBL087)
  • Construction of Genomic Library:
    • Collection of total genomic DNA of a single organism.
    • Each fragment of DNA is stored in a vector (organisms that act as carriers of DNA other than their own DNA to another host and have the capability of being expressed in the host) and innumerable vectors each having a distinct fragment of DNA makes up the gene library.
    • The DNA used to construct the gene library are termed as cDNA, a type of DNA that has been obtained from a single stranded mRNA strand by a process called reverse transcription (the process in which DNA is created from RNA) with the help of a special type of enzyme called reverse transcriptase.
    • At first, a cDNA library is formed and then, segments from this cDNA are cleaved by endonucleases and the cleaved sections are joined with vector DNA by DNA Ligase.
    • Applications:
      • First step in any DNA sequencing projects.
      • Helps in identification of the novel pharmaceutically important genes.
      • Helps in identification of new genes which were silent in the host.
      • It helps us in understanding the complexity of genomes.
      • Serving as a source of genomic sequence for generation of transgenic animals through genetic engineering.
      • Study of the function of regulatory sequences in vitro.
      • Study of genetic mutations in cancer tissues.
      • Create cDNA libraries to determine what genes are being expressed at a particular time.
  • Gene Cloning:
    • Process in which identical copies of a gene are produced.
    • The gene which will be “xeroxed” is termed as the “gene of interest”.
    • At first the gene of interest is selected and is separated from the DNA strand by using restriction endonuclease, an enzyme that cuts DNA at specific sites.
    • Next, a vector is selected that will carry the gene of interest is selected. Plasmid, the extracellular DNA present in the vector contains a target site, a site where the gene of interest will be inserted. The target site in the plasmid is also digested by restriction enzyme.
    • The gene of interest is introduced in the vector and joined with the target site by DNA ligase.
    • The vector containing the gene of interest is placed in an environment suitable for multiplication. We will obtain the targeted protein after the vector starts multiplying. Along with the protein, some chemical materials of the vector will also be present thus, the protein needs to be purified.
    • Applications:
      • DNA cloning can be used to make human proteins with biomedical applications, such as the insulin.
      • Other examples of recombinant proteins include human growth hormone, which is given to patients who are unable to synthesize the hormone, and tissue plasminogen activator (tPA), which is used to treat strokes and prevent blood clots.
      • In basic research labs, biologists often use DNA cloning to build artificial, recombinant versions of genes that help them understand how normal genes in an organism function.
      • Once characterized and manipulated to provide signals for appropriate expression, cloned genes may be inserted into organisms, generating transgenic organisms, also termed genetically modified organisms (GMOs). Although most GMOs are generated for purposes of basic biological research (see for example, transgenic mouse), a number of GMOs have been developed for commercial use, ranging from animals and plants that produce pharmaceuticals or other compounds (pharming), herbicide-resistant crop plants, and fluorescent tropical fish (GloFish) for home entertainment.

Extract from HSC Biology Stage 6 Syllabus. © 2017 Board of Studies NSW.