Post on 11-May-2015
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!