Genetic Engineering Basics

Genetic Engineering

• Genetic engineering is the process of altering DNA in living organisms to create something new.
• Genetically Modified Organisms (GMOs) are organisms whose DNA has been altered.
• Examples include bacteria producing human insulin, illustrating the transfer of genes across species.
• Genetically modified organisms are also called transgenic organisms because genes are transferred from one organism to another.

Genetic Engineering Techniques

• Artificial Selection: Breeders choose organisms to mate, aiming for offspring with desired traits.
  • Selective breeding focuses on choosing the best male and female to breed and maintaining those best traits.
  • Examples of selective breeding include champion race horses, cows with tender meat, or oranges with large juicy fruit.
  • Breeders cannot control the specific genes inherited, but desirable traits are maintained through further breeding.
  • Inbreeding focuses on similar organisms breeding, increasing the risk of genetic disorders in offspring.
  • Hybridization involves crossing two organisms with unlike characteristics to get a desirable combination. Examples include Luther Burbank's disease-resistant potato, a hybridized product combining disease resistance with high yield. Liger (lion and tiger mix) and Grapple (grape and apple mix) are other examples of hybridization.
• Cloning: Creating an exact genetic copy of another organism.
  • Cloning results in organisms genetically identical to a single parent. Identical twins are a natural form of cloning.
  • Cloning involves removing a single cell from a parent organism and growing a complete new organism from that one cell. Cloning is a form of asexual reproduction.
  • Dolly the sheep was the first mammal cloned.
  • Although Dolly had the same DNA as her mother, environmental factors still affected her characteristics.
• Gene Splicing: Cutting DNA from one organism and inserting it into another.
  • This allows for the transfer of specific traits.
  • Examples include genetically modifying bacteria to produce human insulin, a more efficient, and economical method.
  • High tech lab equipment is necessary for gene splicing because DNA is very small.
  • Restriction enzymes are used to cut DNA at specific locations.
    • Restriction enzymes are enzymes that cut DNA at precise code sequences.
    • There are thousands of restriction enzymes, each cutting DNA based on a particular sequence of nucleotides.
    • The DNA segment is cut in places where the sequences indicate.
    • The different cuts produce different fragments.
• Gel Electrophoresis: Analyzing DNA.

Cloning Process

• Step 1: Remove an egg from a female human/animal.
• Step 2: Remove the nucleus from the egg.
• Step 3: Take DNA from a body cell of the required organism and place it in the empty egg cell.
• Step 4: Charge the egg cell with electricity to start mitosis.
• Step 5: Place the cell into a surrogate mother until it grows into a baby.

Cloning Risks

• Decreases genetic diversity.
• If one clone gets a disease, they all potentially get it (due to the same immune system).
• Low success rate (approximately 90% failure rate).
• Expensive.

Benefits of Gene Splicing (e.g., Insulin production)

• Cheaper insulin.
• No side effects because it's human insulin.
• Pigs once produced insulin, but this incurred side effects and was expensive.

Transformation and Transgenic Organisms

• Transformation: Transferring a gene from one organism to another.
• Transgenic organisms: Organisms with transferred genes.
• Biotechnology is the field arisen from genetic engineering (technology of life).

Types of Transgenic Organisms

• Transgenic Animals: Genes inserted into animals to create needed products by animals.
  • Example: Transgenic cows with genes to increase milk production.
  • Example: Spider goats producing spider web silk proteins in their milk.
  • Example: Glow-in-the-dark cats.
• Transgenic Bacteria: Bacteria producing things humans need.
  • Example: Bacteria creating human insulin for medical use.
• Transgenic Plants: Plants given genes to meet human needs.
  • Example: Corn producing pesticide.
  • Example: Cabbage producing insecticide produced from a scorpion's venom.