Genetic Engineering

• Selective breeding or classical breeding altered the genetic make-up of these organisms over the centuries
• Crops now do not resemble their non-domesticated relatives
• Classical breeding


  The traditional way of genetic engineering, practices the mating of organisms with desirable qualities
• Examples of plants and animals that are common and available in our locality

  • Watermelon
  • Banana
  • Eggplant
  • Carrot
  • Corn
• Farmers saved kernels from corn plants with favorable characteristics and planted them
• 2 varieties of bananas were cross-bred. From this process, bananas became what they are today
• Chicken genes are altered to make them always hungry so they will eat and grow more rapidly
• Scientists removed defects and improved growth and meat quality through genetic engineering
• "DNA makes RNA makes Protein" – Marshall Nirenberg
• Nucleic Acids


  Made up of Nucleotides
• Proteins


  Made up of Amino Acids
• Linear polymers


  Single continuous chain of monomers, its specific sequence effectively encodes information
• pancreas doesn't make enough insulin, hormone that regulate blood sugar levels
• Bacteria used for genetic engineering

  • Easy to grow
  • Multiplies quickly
  • Doesn't take up a lot of space
• Recombinant DNA technology


  1. Locate the human gene for insulin production through gene mapping

  2. Remove bacterial plasmid

  3. Use restriction enzymes to cut the plasmid to make space

  4. Use ligase to put the gene into place

  5. Results in a recombinant DNA containing the main DNA and the gene of interest

  6. Use chemicals and temperature changes for the bacteria to accept the rDNA

  7. Once accepted, the recombinant DNA will be inherited once the bacteria clones itself

  8. The recombinant bacteria use the gene to begin producing human insulin

  9. Harvest the insulin from the bacteria

  10. Purify the insulin in the lab to be used for humans
• Genetic engineering


  Changing a target organism's genes/traits using biotechnology tools or techniques
• Modification of traits may involve

  • Introduction of new traits into an organism
  • Enhancement of a present trait by increasing the expression of the desired gene
  • Enhancement of a present trait by disrupting the inhibition of the desired genes' expression
• Vectors used in transformation

  • Plasmids
  • Microinjection
  • Biolistics
  • Heat Shock Treatment
  • Electroporation
  • CRISPR
• Steps in genetic engineering

  1. Cutting or Cleavage of DNA by restriction enzymes

  2. Selection of appropriate Vector

  3. Ligation

  4. Transfer of the Recombinant DNA into a host cell

  5. Selection Process

  6. Sequencing of gene
• Restriction Enzymes (REs)


  Molecular scissors that cut the DNA at specific sites
• Vectors


  Propagate (transmit) the recombinant DNA, plasmids are most commonly used
• Ligation


  The gene of interest and the vector are "joined together" to form the recombinant DNA
• Selection Process


  The cells that actually contain the gene of interest is selected, the recombinant/transgenic cells will carry out the replication to make huge copies of the recombined DNA
• Sequencing of gene


  In order to identify the gene or protein of interest. Depending on the goal, the product will be harvested