Biotechnology

Will it be a Brave New World?

What is biotechnology Biotechnology is using living organisms to

produce something useful for humans Selective breeding--breeding organisms to

produce desirable traits Inbreeding--crossing of organisms that have

similar genotypes so the desirable traits will eventually be homozygous (crops, horses, dogs…not people!!!) Can also increase the chance of harmful recessive

traits showing up

Hybridization Outbreeding--crossing distantly related organisms

Combines desirable traits from different parents Hybrid vigor--larger, healthier offspring may be

produced, but often sterile if different spp. Mule from male donkey and female horse is more docile

than donkey but hardier than a horse Liger

NSSL--National Seed Storage Laboratory--maintains seeds from thousands of plants Allows selective breeding for crops

Genetic Engineering Genetic engineering--identifying or

changing genes Can yield changes in a very short period of

time Same techniques used to ID people

Gel Electrophoresis Used to sort fragments/molecules by size An Overview from PBS--http://www.pbs.org/wgbh/nova/sheppard/analyze.html

Restriction enzymes cut DNA into smaller fragments Cut DNA at specific locations based on the base pair

sequence Different restriction enzymes cut the DNA at different

locations Sticky ends--unpaired base sequences that exist after the

DNA is cut NOTE: R.E.’s can be isolated from bacteria--enable

them to chop up DNA of invading viruses!

Gel electrophoresis (Fig 5-p.231) DNA fragments put into a gel Tracks have a positive charge at one end and

negative at the other The negatively-charged DNA moves toward the

positive end Smallest fragments move the furthest Fragments are dyed to get visible bands DNA fingerprint is formed Can ID person or find certain gene

Changing genomes Recombinant DNA--formed when DNA is

combined from different organisms Human genes that produce human proteins can be

added to bacteria or yeast to mass produce the proteins

Vector--carrier of the DNA Genes are spliced into the genome of the vector by

utilizing restriction enzymes and sticky ends Plasmid--small circular pieces of DNA found in

bacteria Viruses

MakingMakingINSULININSULIN

Human Human DNADNA

RestrictRestriction ion enzymes enzymes cut the cut the DNADNA

DNA DNA Fragments Fragments with with “Sticky “Sticky Ends”Ends”

Small, Small, CirculaCircular, r, BacteriBacterial DNA al DNA ==PlasmidPlasmid

RestrictioRestriction enzyme n enzyme cuts the cuts the plasmidplasmidInsulin Insulin gene gene inserted inserted into into plasmidplasmid

rDNA rDNA used as used as vectorvector

Another view of restriction enzymes at work

The Size of stuff

Agricultural applications of genetic engineering Crops

Transgenic organisms--altered by adding a gene from another species

May confer disease, drought, or pest resistance, or give other desirable traits to plants

May allow animals to produce more/better milk, meat, etc.

Medicinal applications Gene therapy--changing the genes that cause a

disorder (e.g. cystic fibrosis, hemophilia, clogged arteries)

Vaccines/medicines now produced: Hepatitis B vaccine Human growth hormone Multiple sclerosis Insulin Cancer???

Diagnosis with genetics Early detections with the use of genetic

markers (e.g. Huntington’s Disease, retinoblastoma)

Knowledge--the future is limitless with the findings of the genome project

Genetics and forensics Crimes Family relationships Positive ID of a person

The Ethical Dilemma Potential abuse and accidents pose a risk

for genetic engineering Deadly/harmful bacteria and viruses could

be released into environment Unknown effects of “superorganisms”

Ethical considerations Should I be able to:

Alter my bad genes before I pass them on? Alter the physical or intellectual traits of my

children? Know the genetic profile of potential

employees? Patent genetic information? Clone an individual or their organs?

Sources of values Where do our values originate?

You decide…I’m not filling in this list for you!