Genetic Engineering
description
Transcript of Genetic Engineering
Genetic Engineering
Biotechnology and Recombinant DNA
Biotechnology
The use of microorganisms, cells, or cell components to make a product:• Foods• Vaccines• Antibiotics• Vitamins• Biodegradation
Genetic Engineering
• Manipulating an organism’s genome to:• alter microbes, plants, and animals
for our benefit
• correct genetic defects in humans
Ex: Golden Rice
• Created to provide people with Vitamin A
• Developed to help the very poor
Ex: Flavr Savr Tomato
• Created to prevent the softening of the tomato
• Made more resistant to rotting
• Could be “vine-ripened”
Ex: Glofish
• Inserted fluorescent gene from a jellyfish into zebrafish
• Sold as a pet
Ex: Roundup Ready Soybeans
• Soybeans that are resistant to Roundup herbicide
• Created to reduce the application of harmful herbicides
Bioethics Warm-UpWhich human traits do you think are acceptable to genetically modify?
Which human traits aren’t acceptable to genetically modify?
Bioethics Warm-Up
Would you want to know if you were genetically predisposed to a certain disorder (like heart disease or diabetes)?
What if it was for a disorder that has no known treatment?
Glowing Animals
Other Uses of Genetic Technology
• Used to identify individuals:– Suspects in a crime (“DNA fingerprinting”)
Other Uses of Genetic Technology
• Used to identify individuals:– Relation between
individuals:• Ex: paternity tests
Other Uses of Genetic Technology
• Used to identify individuals:– Relation between
individuals:• Ex: University of
Arizona Shoah Project to identify and reunite the families of Holocaust victims
DNA
• DNA is universal – the genetic information from one species will work in another species
• “DNA is DNA”
DNA 101 – Quick Refresher
• DNA formed from units called nucleotides
• Each nucleotide is made of:– 5 carbon sugar (deoxyribose)– Phosphate group– Nitrogenous base
• Adenine• Guanine• Cytosine• Thymine
DNA 101 – Quick Refresher
• In all DNA:– A pairs with T– C pairs with G
• Weak hydrogen bonds form between complimentary base pairs
Bioethical Question
• Should a company be allowed to patent (and own the exclusive rights of) a genetically modified organism?
Useful Properties of DNA
• Restriction Endonuclease – enzymes used to cut apart DNA strands
Useful Properties of DNA
• Restriction enzymes can cut DNA at specific sites, leaving “sticky ends” for insertion of new DNA
• Ligase – enzyme used to “glue” strands together
DNA Manipulation
Restriction Endonucleases
• Also called restriction enzymes• 1962: “molecular scissors” discovered
in in bacteria• E. coli bacteria have an enzymatic
immune system that recognizes and destroys foreign DNA
• 3,000 enzymes have been identified, many are purified and available commercially
Restriction Endonucleases
• Named for bacterial genus, species, strain, and type
Example: EcoR1
Genus: EscherichiaSpecies: coliStrain: ROrder discovered:
1
“Sticky Ends” vs. “Blunt Ends”
Restriction Endonuclease
• Restriction enzymes recognize specific palindromic sequences and cut them– Palindromes: words that are the same
forwards and backwards• Ex: Stanley Yelnats• Ex: Go hang a salami, I’m a lasagna hog• Ex: Anna• Ex: A man, a plan, a canal, Panama!• Ex: Wet sanitary rat in a stew.
Bioethical Issues
• Should we be able to insert non-human DNA into human DNA?
• Would this change what it means to be “human”?
• Should humans be able to alter our intelligence via genetic engineering?
Warm-Up
• If there aren’t any risks associated with GM foods, should companies be required to label foods made with GMOs?
Recombinant DNA
• Recombinant DNA: DNA from two or more species that has been joined together
• Transgenic: organisms altered by genetic engineering
Warm-Up
• Genetic pollution: undesired and uncontrolled gene flow from GMOs into wild populations
• What are the implications of “genetic pollution”?• Should we try to prevent “genetic pollution”?
Other Uses