Aim: How can we change DNA to do what we want? DO NOW: Write down a trait or a characteristic that you would want that exist in another organism. Aim: How can we change DNA to do what we want?

Where do we get insulin from? Insulin is an important hormone produced by the pancreas. Insulin lowers blood sugar. People who suffer with diabetics cannot produce their own insulin. Diabetics need to inject lots of insulin to survive. So where do you think this insulin comes from? BACTERIA

Where do we get insulin from? Special Ecoli Bacteria produces human insulin. HOW??? Scientist insert a human gene into a bacteria’s DNA. Why bacteria and not humans cells? Bacteria grow and multiply very fast and can product insulin cheaply. If you try to fix a pancreas cell, you would have to fix all hundred thousand of them which would be impossible.

What is Genetic Engineering? Using a process called genetic engineering, we can modify DNA. Genetic engineering is the transfer of genetic material (a Gene) from one organism to another. The example used is inserting the human gene for insulin into a bacteria’s DNA.

Overview of Genetic Engineering Human Cell Gene for insulin Recombinant DNA Sticky ends DNA recombination DNA insertion Bacterial Cell Plasmid Bacterial chromosome Bacterial cell for containing gene for insulin

Genetic Engineering in just 6 easy steps chromosome 11 Find the gene for insulin in a human’s DNA: The insulin gene is located on chromosome 11.

2. Cut the insulin gene out of the human DNA using a restriction enzyme. Restriction enzyme is an enzyme that cuts the DNA at a specific base sequence. REMEMBER: Enzymes are proteins and proteins are shape specific.

CACTTAGCGACACTTAA GTGAATCGCTGTGAATT CACTTAGCGACACTTAA cut by restriction enzyme cut by restriction enzyme This restricted enzyme cuts at the sequence ACTTA AGCGACACTT GAATCGCTGT insulin gene

bacterium plasmid restriction enzyme 3. Use the same restriction enzyme to cut open the bacteria’s DNA (plasmid). What do you notice about the bacteria’s DNA that is different? Bacteria DNA is round not ladder-like. bacterium plasmid restriction enzyme

4. Insert the human insulin gene into the plasmid and “glue it” using the same restrictive enzyme.. =

5. Put the plasmid (DNA) back into the bacteria and allow the bacteria to reproduce asexually (mitosis).

6. Since each new bacterium has the human gene for insulin, each one of the “new” bacteria produces insulin when its genes are expressed. insulin

Pros and Cons Pros Cons Scientist can make “better” organisms. Scientist can tailor make an organism any way they want. Cons Very expensive to begin (lots of research). Is it OK to mix genes of different species?

Some Examples of Genetic Engineering

So Let’s Review Selective Breeding Cloning Genetic Engineering Age of technique Old or new Old Technique (1000’s of years) New Technique Who usually performs this technique. Farmers or Scientist Farmers Scientist Parents Two parents, both with different desired traits One Parent Two different Species- 1 with DNA, another for a gene Offspring Offspring with desired traits from both parents Identical to parent Offspring has a new gene in its DNA from another species. Pros Cheap, anyone can do it, get offspring that you want You can make more of something you want. You know what you are going to get. Can be used to make an organism better. Can make hormone cheaply. Cons Not guaranteed to get the desired offspring. Takes a long time for consistency. Lowers diversity. What kills one offspring will kill the others. Expensive Ethics. Is it OK to mix genes of different species?