Transcript Biotechnology_PZ - Kenston Local Schools

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 …?
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Food / Crop yield
Medicine / Health Issues
Disease / illness – transplants
Vaccines
Livestock
Law Enforcement (DNA Fingerprinting)
Bioremediation
Mouse: Mus musculus
LE 21-3
Fertilized frog eggs: one week
Fertilized egg of a frog
Tadpole hatching from egg
Restriction enzymes:
• DNA Scissors
• Restriction
Microarray – Gene Chip
Can determine thousands of different genes at one time
LE 20-8
Cathode
Power
source
Mixture
of DNA
molecules
of different sizes
Shorter
molecules
Gel
Glass
plates
Anode
Longer
molecules
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
Insert RNA version of normal allele
into retrovirus.
Viral RNA
Retrovirus
capsid
Let retrovirus infect bone marrow cells
that have been removed from the
patient and cultured.
Viral DNA carrying the normal
allele inserts into chromosome.
Bone
marrow
cell from
patient
Inject engineered
cells into patient.
Bone
marrow
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 20-17
Defendant’s
blood (D)
Blood from defendant’s
clothes
Victim’s
blood (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
Mammary
cell donor
Egg cell
donor
Egg cell
from ovary
Cultured
mammary cells
are semistarved,
arresting the cell
cycle and causing
dedifferentiation
Nucleus
removed
Cells fused
Nucleus from
mammary cell
Grown in culture
Early embryo
Implanted in uterus
of a third sheep
Surrogate
mother
Embryonic
development
Lamb (“Dolly”) genetically identical
to mammary cell donor
Cloning
• Since 1997, cloning has been
demonstrated in many mammals,
including:
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Mice
Cats
Cows
Horses
Pigs
• “Copy Cat” was the first cat cloned
“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
Totipotent
cells
Adult stem cells
Pluripotent
cells
Cultured
stem cells
Different
culture
conditions
Different
Liver cells
types of
differentiated
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.
EPIGENETICS
You are more than
your DNA
University of Utah
• http://learn.genetics.utah.edu/content/epig
enetics/intro/
• http://genome.ucsc.edu/cgibin/hgTracks?hgS_doOtherUser=submit&
hgS_otherUserName=Kate&hgS_otherUs
erSessionName=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
Leg
Antenna
Wild type
Mutant
LE 21-14a
Tail
Head
Wild-type larva
Tail
Tail
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
Adult
fruit fly
Fruit fly embryo
(10 hours)
Fly
chromosome
Mouse
chromosomes
Mouse embryo
(12 days)
Adult mouse
LE 21-24
Thorax
Thorax
Genital
segments
Abdomen
Abdomen
The End