DNA technology

• Gene cloning• Gene therapy• Biopharmaceuticals• Forensics

– DNA fingerprinting, PCR

• Genomics– Human Genome Project

• Frankenfoods– Genetically modified crops

Recombinant DNA & Plasmids Combining genes from different sources and/or species

• Circular DNA from bacteria = plasmids

• Target DNA recombined in plasmid

• Bacteria rapidly reproduces many clones

How is this possible?

• Enzymes– Used to “cut and paste”– Restriction enzymes

• Cuts DNA into fragments– remember DNA lab

– DNA ligase• Pastes fragments from one

source into another

Biopharmaceuticals• Use recombinant cells to

mass produce proteins– Bacteria– Yeast– Mammalian

• Insulin– Hormone required to

properly process sugars and fats

– Treat diabetes – Now easily produced

by bacteria

• Growth hormone deficiency– Faulty pituitary and

regulation– Had to rely on cadaver

source– Now easily produced

by bacteria

Not always used for good...

• High doses of HGH can cause permanent side effects– As adults normal growth

has stopped so excessive GH can thicken bones and enlarge organs

Forensics

• DNA profiling or DNA fingerprinting

• Requires only small samples (saliva, blood, semen, etc.) left at a crime scene

• Probability up to 1 in a billion

• e.g. O.J. Trial, CSI, Law & Order…

PCR

• Polymerase chain reaction– Used to amplify or

make many DNA copies of a small sample

Genetically modified organisms (GMO)

• Use of recombinant plasmids in agriculture– plants with genetically

desirable traits• herbicide or pesticide resistant

corn & soybean– Decreases chemical

insecticide use– Increases production

• “Golden rice” with beta-carotene

– Required to make vitamin A, which in deficiency causes blindness

Other benefits of GMOs

• Disease resistance– There are many viruses, fungi, bacteria that cause

plant diseases– “Super-shrimp”

• Cold tolerance– Antifreeze gene from cold water fish introduced to

tobacco and potato plants

• Drought tolerance & Salinity tolerance– As populations expand, potential to grow crops in

otherwise inhospitable environments

Where in the world?

Downsides???

• Introduce allergens?

• Pass trans-genes to wild populations?– Pollinator transfer

• R&D is costly– Patents to insure profits

• Patent infringements• Lawsuits• potential for capitalism to

overshadow humanitarian efforts