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Genetic Engineering
DNA is universal
Selective Breeding Long history of
manipulating genes Speed- horses
Strength- oxen
Larger fruit
Science of Genetic Engineering
Moving genes from one organism to another.
Based upon genetics
Began in the 1970’s- manipulations of bacteria, viruses and plasmids
Processes of Genetic Engineering
1. Recombinant DNA2. DNA Fingerprinting3. Polymerase chain reaction4. Cloning
Chimera
First Chimera1973- Cohen & Boyer
Isolated the gene – for rRNA from an
African clawed toad
Inserted it into a bacterium
Tools of Genetic Engineering
Restriction enzymes
Ligase
Vectors
Gel electrophoresis
PCR
Restriction Enzymes- endonucleases
Discovered in 1968- origin Bacteria
Chemical scissors
Used as a defense mechanisms against foreign DNA.
100’s have been
identified
Bind to a specific sequence (4-6) nucleotides.
They cut the DNA leaving sticky ends
EcoRI
Named for the organism of origin.
Restriction Enzymes- blunt ends
Hemophilus aegypticus ( HaeIII)
LigaseAn enzyme that
binds nucleotides together
“Super glue” – genetic engineering
Vectors
Something that delivers a biological material from one organism to another.
Plasmids
Bacteria
Extra DNA – separate from the main genome (nucloid)
Ability to replicate
1,000 – 20,000 base pairs
VirusesViruses have evolved
mechanisms to transport their genomes into a host cell.
Transduction- delivery of a gene by a virus.
Pathogenic viruses are modified to minimize risk.
Gene guns and metal bullets
Delivery system designed for injecting cells with genetic information.
“biolistic particle delivery system”
Payload is an elemental particle coated with a plasmid.
Recombinant DNAThe process of
creating a chimera.
“Splicing a gene/genes from one organism into the genome of a different organism”.
Paper Recombinant DNA
Genetically Modified OrganismGMO
Organism that has acquired 1 or more genes by artificial means
New be from another species
Transgenic- an organism contains a gene from another organism.
BacteriaOften the organism
of choice:1. Grow quickly2. Low costs3. Easily engineered
to secrete into a growing medium
H. Insulin- Humulin 1982
H growth hormone Epidermal growth
hormone Interleukin2 –
cancer Taxol – cancer
Yeast
Eukaryotes Single celled Contain plasmids
Yeast are:
Easy to grow Take up foreign
DNA Better at
synthesizing and secreting eukaryotic proteinsHepatitis B
vaccineInterferon- cancer, viruses
“Pharm” animalsMAMMALS
Many of the proteins that are secreted by humans are glycoproteins.
Only mammals can correctly add the sugar to these proteins.
When a gene of interest is inserted into a specific mammary cell= it will be secreted into the milk.
Milk medicine
1. Erythropoitin- anemia
2. Factor VIII- hemophilia
Genetically modified organisms
GoatsGoats contain gene
that codes for spider silk.
Extracted from milk.
Bullet proof vests Artificial tendons clothing
Tumor resistant mouse Contains a gene
that codes for a protein called par-4
Kills cancer cells not normal cells.
Emerald Sea Slug Believed to be the first
known, naturally occurring transgenic animal.
Feeds on algae- capable of using the algae to carry out photosynthesis.
Found a gene in the slug with the same genetic sequence as algae.
l
Glofish 1st commercial
transgenic animal Contain a gene
from jellyfish that allow cells to fluoresce
Aedes mosquito Genetically
engineered to be sterile
Mate with females Population of
mosquitos reduced.
Less disease like dengue fever that has no vaccine or cure.
Mighty mouse Genetically altered
to over-produce the enzyme PEPCK-C involved in glucose generation.
Runs 25x longer
Affects on aging
Transgenic chickens Able to express
foreign products in their eggs.
Goal for chickens to produce eggs with life saving drugs.
GM and AgricultureHow to feed a
growing population?
Use a soil bacterium :
Agrobacteria tumifaciens
Ti plasmid
ApplicationsMost Soybeans and
cotton crops are GM.
Pesticide resistant Glycophosphate
resistant “round-up”
Pest resistant
To improve nutritional value of crops.
Golden rice- contain daffadil gene ( beta-carotene)-
reduce blindness
Risks of GM food
Animals: What if a cancer cell
was transferred to a virus or bacterium.
Crops: Allergies Gene drift to nearby
crops. Hazardous to human
health
Government Regulations
Strict laboratory procedures
Genetically altered microbes must be
disabled. Dangerous
experiments have been banned
BioremediationBacteria- clean up
wastes.1. Take up mercury-
pollution2. Extract pesticide
vapors from the air
3. Take up petroleum from spills
EnviropigEngineered to
produce and enzyme in its saliva which breaks down phosphorus in their feces.
Reduces pollution Marine pollution-
runoff Greenhouse gases
Gel electrophoresis Acts like a sieve to
separate out DNA fragments by size.
Separates linear pieces of DNA into bands.
Length : distance
RFLP’s DNA from different people- cut with
the same restriction enzyme =
RFLP’s- restriction fragment length polymorphisms.
Electrophoresis- generates a fingerprint that shows relationship between organisms.
Application of DNA Fingerprints Determine paternity- T.
Jefferson – Sally Hemings
Forensics- solving cold cases
Identifying endangered species trafficing
Identify genes that cause genetic disorders
billion copies of a DNA – few hours
Simple process: DNA DNA polymerase Nucleotide
monomers Heating and
cooling
Ancient DNA – wholly mammoth
Forensics- blood, semen, tissue
Prenatal diagnosis of genetic disorders
DNA from viral genes from infected cells
PCR- Polymerase Chain Reaction
