Genetic Engineering

What is Genetic Engineering? Genetic engineering: Changing the DNA in living organisms to create something new. These organisms are called Genetically Modified Organism (GMO) Genetically Modified organism are called transgenic organism; since genes are transferred from one organism to another. trans: means different, genic: refers to genes

Some genetic engineering techniques are as follows: 1. Artificial selection A. selective breeding B. hybridization C. inbreeding 2. Cloning 3. Gene splicing 4. Gel electrophoresis: analyzing DNA

What is artificial Selection? artificial selection: breeders choose which organism to mate to produce offspring with desired traits. They cannot control what genes are passed. When they get offspring with the desired traits, they maintain them.

A. Selective breeding: when animals with desired characteristics are mated to produce offspring with those desired traits. Passing of important genes to next generation. Example: Champion race horses, cows with tender meat, large juicy oranges on a tree.

Examples of selective breeding: Angus cows are bred to increase muscle mass so that we get more meat, Egg-Laying Hen-produces more eggs than the average hen

B. Hybridizations: two individuals with unlike characteristics are crossed to produce the best in both organisms. Example: Luther Burbank created a disease resistant potato called the Burbank potato. He crossed a disease resistant plant with one that had a large food producing capacity. Result: disease resistant plant that makes a lot of potatoes.

Other Examples of hybridization: Liger: lion and tiger mix

2. Grape + apple= grapple. The fruit tastes like grapes and looks like apple.

C. Inbreeding breeding of organism that genetically similar to maintain desired traits. Risk: since both have the same genes, the chance that a baby will get a recessive genetic disorder is high. Ex. Dogs breeds are kept pure this way. It keeps each breed unique from others.

There are human clones in our school. 2. Cloning: creating an organism that is an exact genetic copy of another (the parent). There are human clones in our school. identical twins are naturally created clones. Ex. Dolly

3. Gene splicing (aka: Recombinant DNA): DNA is cut out of one organism and put into another organism A trait will be transferred from one organism to another. For example: the human insulin gene can be removed from a human cell. It can be put into a bacterial cell. The bacterial will now make human insulin.

Recombinant Bacteria Remove bacterial DNA (plasmid). Cut the Bacterial DNA with “restriction enzymes”. Cut the DNA from another organism with “restriction enzymes”. Combine the cut pieces of DNA together with another enzyme and insert them into bacteria. Reproduce the recombinant bacteria. The foreign genes will be expressed in the bacteria.

1. Transgenic (GMO) animals: genes inserted into animals so they produce what humans need. Why?: A way to improve the food supply: A. Transgenic cows: gene inserted to increase milk production.

B. Spider goat: gene from spider inserted into goat. Goats makes silk of the spider web in their milk. Flexible, stronger than steel. Used in bullet proof jackets.

C. Glow-in-the-dark cats  Scientist used a virus to insert DNA from jellyfish The gene made the cat produce a fluorescent protein in its fur.  

2. Transgenic bacteria: gene inserted into bacteria so they produce things humans need. For example: insulin and clotting factors in blood are now made by bacteria.

3. Transgenic plants: plants are given genes so they meet human needs. A. Transgenic corn: given a gene so corn produces a natural pesticide. Now they don’t have to be sprayed with cancer causing pesticides. 25% of all corn is like this.

B. Venomous cabbage gene from a scorpion tails inserted into cabbage. Cabbage now produces that chemical. Why? Limit pesticide use while still preventing insects from damaging crops. Corporations state the toxin is modified so it isn’t harmful to humans.

C. Banana vaccines virus is injected into a banana, the virus DNA becomes part of the plant. As the plant grows, it produces the virus proteins — but not the disease part of the virus. When people eat a bite, their immune systems creates antibodies to fight the disease — just like a traditional vaccine Vaccines for hepatitis and cholera

A virus is often used to deliver DNA. In the movie “I Am Legend,” A healthy gene was inserted into a virus. The virus invaded the cancer cells and inserts the healthy gene to cure cancer. Worked at first but the virus mutated and became deadly. This is being attempted in real life.

Gene therapy: when disease causing genes are cut out and good gene are inserted. Restriction enzymes are used to cut out bad genes. Viruses are used to insert good genes. Not approved for human use yet. Some possible side effects.

Gel electrophoresis: a technique used to compare DNA from two or more organisms. Why compare DNA: Find your baby’s daddy Who committed a crime. How closely species are related.

Steps Involved in Gel Electrophoresis 1. “Cut” DNA sample with restriction enzymes. 2. Run the DNA fragments through a gel. 3. Bands will form in the gel. 4. Everyone’s DNA bands are unique and can be used to identify a person. 5. DNA bands are like “genetic fingerprints”.

Electrophoresis results Separation of DNA based on size of fragments. Electrophoresis results Final result of electrophoresis

Electricity provides the energy Why does DNA move? DNA has a negative charge. When the machine is plugged it, its moves towards the positive pole created by the electricity

Your DNA is so unique its considered to be a DNA fingerprint. Gel electrophoresis will separate your DNA differently from anyone else. Nova: who done it http://www.pbs.org/wgbh/nova/sheppard/analyze.html http://www.teachersdomain.org/asset/tdc02_int_creatednafp2/