biotechnology. ~~ marriage of biology & technology ~~ biotechnology used in industry –genetic...
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Biotechnology
• ~~ Marriage of biology & technology ~~
• Biotechnology used in industry– Genetic Engineering– Gene Therapy– Stem Cells / Stem Cell Transplant– Genetically Modified Organisms
• food = plants / animals
Another definition of biotechnology …
• “The deliberate manipulation of DNA molecules to produce commercial products from living organisms.“– Scientists are learning how to transfer genes
from one animal, plant, or other organism into another
Importance to you …?
• Food / Crop yield
• Medicine / Health Issues
• Disease / illness – transplants
• Vaccines
• Livestock
• Law Enforcement (DNA Fingerprinting)
• Bioremediation
Mouse: Mus musculus
LE 21-3
Fertilized egg of a frog Tadpole hatching from egg
Fertilized frog eggs: one week
Restriction enzymes:
• DNA Scissors • RestrictionRestriction
Microarray – Gene Chip
Can determine thousands of different genes at one time
LE 20-8
Cathode
Powersource
Anode
Mixtureof DNAmoleculesof differ-ent sizes
Gel
Glassplates
Longermolecules
Shortermolecules
Human Gene Therapy
• Gene therapy is changing / putting in “good” genes
• Gene therapy works best when disease is caused by only one defective gene
• Vectors (viruses) are used for delivery of genes into cells
LE 20-16
Cloned gene
Retroviruscapsid
Bonemarrowcell frompatient
Inject engineeredcells into patient.
Insert RNA version of normal alleleinto retrovirus.
Viral RNA
Let retrovirus infect bone marrow cellsthat have been removed from thepatient and cultured.
Viral DNA carrying the normalallele inserts into chromosome.
Bonemarrow
Forensic Evidence
• DNA “fingerprints” from samples of body fluids or tissue can provide evidence in criminal and paternity cases
• A DNA fingerprint is a specific pattern of bands
LE 20-17Defendant’sblood (D)
Blood from defendant’sclothes
Victim’sblood (V)
Environmental Cleanup ”Bioremediation”
• Genetic engineering can be used to design bacteria to clean up oil spills
• Some bacteria can be used to degrade potentially toxic waste materials
Agricultural Applications
• DNA technology is being used to improve agricultural productivity and food quality
Animal Husbandry and “Pharm” Animals
• Transgenic organisms are made by introducing genes from one organism into the genome of another organism
• Pharmaceutical “factories,” producers of antibiotics
Safety and Ethical Questions Raised by DNA Technology
• Potential benefits of genetic engineering must be weighed against potential hazards of creating harmful products or procedures
• Most public concern is about:– genetically modified (GM) organisms
Reproductive Cloning of Mammals
• In 1997, Scotland – Dolly was the first mammal cloned (a lamb)– from a differentiated mammary cell
• Dolly’s premature death in 2003, as well as her arthritis, led to speculation that her cells were “older” than those of a normal sheep
LE 21-7
Mammarycell donor
Egg celldonor
Egg cellfrom ovary Nucleus
removedCells fusedCultured
mammary cellsare semistarved,arresting the cellcycle and causingdedifferentiation
Nucleus frommammary cell
Early embryo
Grown in culture
Implanted in uterusof a third sheep
Surrogatemother
Embryonicdevelopment
Lamb (“Dolly”) genetically identicalto mammary cell donor
• Since 1997, cloning has been demonstrated in many mammals, including:– Mice– Cats– Cows– Horses– Pigs
• “Copy Cat” was the first cat cloned
Cloning
“Copy Cat”
The Stem Cells of Animals
• A stem cell is an unspecialized (undifferentiated) cell that can reproduce itself indefinitely and differentiate into specialized cells of several types
LE 21-9
Embryonic stem cells Adult stem cells
Pluripotentcells
Totipotentcells
Culturedstem cells
Differentcultureconditions
Differenttypes ofdifferentiatedcells
Liver cells Nerve cells Blood cells
HUMAN GENOME PROJECT
Human Genome Project
• 13-year project coordinated by the U.S. Department of Energy and the NIH
• GOALS:– identify the 20,000-25,000 genes in human
DNA– determine the sequences of the 3 billion base
pairs– address the ethical, legal, and social issues
that may arise from the project.
EPIGENETICSYou are more than
your DNA
University of Utah
• http://learn.genetics.utah.edu/content/epigenetics/intro/
• http://genome.ucsc.edu/cgi-bin/hgTracks?hgS_doOtherUser=submit&hgS_otherUserName=Kate&hgS_otherUserSessionName=encodePortalSession
NIH - Epigenomics
• http://www.ncbi.nlm.nih.gov/epigenomics
Epigenome Project
• http://www.roadmapepigenomics.org/
Hox Genes
• Help lay out the basic body forms of many animals– EX: humans, flies, and worms.
• They set up the head-to-tail organization.
• You can think of them as direct instructions as an embryo develops: – “Put the head here! Legs go over there!”
Identity of Body Parts
• Drosophila has master regulatory genes called homeotic genes = HOX Genes
• Mutations to homeotic genes produce flies with strange traits, such as legs growing from the head in place of antennae
LE 21-13
Eye
AntennaLeg
Wild type Mutant
LE 21-14a
Head
Tail
Tail
Tail
Wild-type larva
Mutant larva (bicoid)
Drosophila larvae with wild-type and bicoid mutant phenotypes
Widespread Conservation of Developmental Genes Among Animals
• Analysis of the hox genes in fruit flies has shown that they all include a sequence called a homeobox
• An very similar sequence has been discovered in both vertebrates and invertebrates
LE 21-23
Adultfruit fly
Fruit fly embryo(10 hours)
Flychromosome
Mousechromosomes
Mouse embryo(12 days)
Adult mouse
LE 21-24
Thorax AbdomenGenitalsegments
Thorax Abdomen
The End
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