Download + – DNA

Goal 3.04 Assess the impacts of genomics
on individuals and society.
There are many
ways that humans
have manipulated
genes.
blog.makezine.com
Let’s look at a few of these…
scrapetv.com
1. ARTIFICIAL BREEDING/SELECTION
Artificial Breeding/Selection is …
When humans select who
mates to whom to improve the
breed.
michaeldodsracing.co.uk
z.about.com
Artificial Breeding/Selection
Wild mustard plant
Artificial Breeding/Selection is …
Wild corn called
TEOSINTE was
bred to create
today’s corn
When humans select
which plants to cross
to improve the plant.
Wild rose plant
nescent.org
Artificial Breeding/Selection
What if humans selected which humans to mate?!
static.howstuffworks.com
www.enjoyfrance.com
?
Angelina Jolie?
Mother Teresa?
gandt.blogs.brynmawr.edu
2009.wimbledon.org
Venus Williams?
Rosalind Franklin?
2. BIOTECHNOLOGY
Biotechnology is …
The use of organisms
or their products to
improve human life.
HOW DO THEY DO IT?!
biotechresearchandfinance.com
The code is UNIVERSAL!
• Since all living
organisms…
– use the same DNA
– use the same code
book
– read their genes the
same way
CLONING = making genetically identical copies
The Controversy
Reversing Human Destruction
through Cloning
http://player.discoveryeducation.com
/index.cfm?guidAssetId=4CDB02CD
-6421-42B4-AF9DB940E1393F19&blnFromSearch=1
&productcode=US
HSW: Genetics: Cloning Time: 03:20
Let’s look at Dolly
Human Genome Project
Identified the entire sequence of DNA bases for humans.
There are 3.2 billion bases in the human genome.
What do you think can
be done now that we
know the order
(sequence) in which all
3.2 billion bases occur?
Human Genome Project Explained 15:24 min
http://www.5min.com/Video/The-Human-Genome-Project-Applications-151426688
KARYOTYPE = display of chromosomes laid out in pairs from largest to smallest. Sex
chromosomes are always placed at the end.
Now, how many chromosomes do you see?
Is this a male or female?
How many chromosomes do you see?
How many chromosomes?
Which
(sex)?
Howgender
many chromosomes?
Which gender (sex)?
Karyotypes are a way or organizing chromosomes to make it
easier to study and identify certain characteristics within an
individual’s DNA.
Make a Karyotype
http://learn.genetics.utah.edu/content/begin/traits/karyotype/
How scientists and doctors use karyotypes
http://learn.genetics.utah.edu/content/begin/traits/predictdisorder/
What do you get when you cross …
instanta.blogspot.com
i57.photobucket.com
www.chemcases.com
clouddragon.wordpress.com
www.scienceclarified.com
Genetic Engineering is…
Inserting genes from one
organism into a different
organism.
smh.com.au
How do we do mix genes??
• Genetic engineering
– find gene
– cut DNA in both organisms
– paste gene from one creature into other creature’s
DNA
– insert new chromosome into organism
– organism copies new gene as if it were its own
– organism reads gene as if it were its own
– organism produces NEW protein:
Remember: we all use the same genetic code!
Cutting DNA
• DNA “scissors”
– enzymes that cut DNA
– Restriction Enzymes
• used by bacteria to cut up DNA of
attacking viruses
• EcoRI, HindIII, BamHI
– cut DNA at specific sites
• enzymes look for specific base sequences
ACTGA ATTCGGATCA
TGACTTAAGCC TAGT
Restriction enzymes

• Cut DNA at specific sites - leave “sticky ends”
Locate the section of gene we want.
Restriction Enzyme
restriction enzyme cut site
GTAACGAATTCACGCTT
CATTGCTTAAGTGCGAA
DNA double
strand.
restriction enzyme cut site

GTAAC
GAATTCACGCTT
CATTGCTTAAG
TGCGAA
Recombining DNA – Use the same enzymes for both pieces.
– leave “sticky ends” on both
– can glue DNA together at “sticky ends”
GTAAC
GAATTCACGCTT
CATTGCTTAAG
TGCGAA
GTAAC
GAATTCACGCTT
CATTGCTTAAG
TGCGAA
DNA Ligase joins the ends.
GTAAC
CATTGCTTAAG
TGCGAA
GAATTCACGCTT
Recombinant DNA:
DNA with foreign genes inserted.
How can
bacteria read
human DNA?
Why use Bacteria??
• Recombined Gene produces needed protein in a
different organism.
• Use Bacteria because it reproduces rapidly and is
one-celled so easy to grow.
20 minutes
10 bacteria
100 minutes
60 minutes
40 bacteria
160 bacteria
6 hours
200 minutes
5120 bacteria
1,310,720 bacteria
Bacterial DNA and plasmids
• Single circular chromosome
– only one copy = haploid
– no nucleus
• Other DNA = plasmids!
plasmids
bacterial
chromosome
How can plasmids help us?
• A way to get genes into bacteria easily
– insert new gene into plasmid
– insert plasmid into bacteria = vector
– bacteria now expresses new gene
• bacteria make new protein
gene from
other organism
cut DNA
plasmid
recombinant
plasmid
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vector
glue DNA
transformed
bacteria
Grow bacteria…make more
gene from
other organism
recombinant
plasmid
+
vector
plasmid
grow
bacteria
harvest (purify)
protein
transformed
bacteria
Virtual Lab 12:
Bacterial Transformation-Ampicillin Resistance
Other uses of Genetic Engineering:
• Genetically modified organisms (GMO)
– enabling plants to produce new proteins
• Produce medications: insulin
– Used by diabetics
• Extend growing season: fishberries
– strawberries with an anti-freezing gene from flounder
• Improve quality of food: golden rice
– rice producing vitamin A
Genetic Engineering and Medicine
Gene Therapy = using genetic engineering to combat disease.
Hemophilia – patients
suffer from a lack of
Factor VIII.
Stem Cells…the key to our future?
Heart Cells
to repair damaged
heart tissues.
Red Blood Cells
for accident victims
and transfusions.
Muscle Cells
to repair damaged or
weak muscles.
Stem Cells
Stem Cells
Biotechnology
Gel Electrophoresis
http://videos.howstuffworks.com/hsw/11820-geneticsusing-dna-evidence-to-solve-crimes-video.htm
Many uses of restriction enzymes…
• Now that we can cut DNA with restriction
enzymes…
– we can cut up DNA from different people… or
different organisms…
and compare it
– why?
• forensics
• medical diagnostics
• paternity
• evolutionary relationships
• and more…
Comparing cut up DNA
Gel Electrophoresis
• How do we compare DNA fragments?
– separate fragments by size
• How do we separate DNA fragments?
– run it through a gelatin
– gel electrophoresis
• How does a gel work?
http://www.dnatube.com/video/701/DNA-Fingerprinting
Gel electrophoresis
• A method of separating DNA
in a gelatin-like material using
an electrical field
– DNA is negatively charged
– when it’s in an electrical field it
moves toward the positive side
DNA
–

“swimming through Jello”
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Gel electrophoresis
• DNA moves in an electrical field…
– so how does that help you compare DNA
fragments?
• size of DNA fragment affects how far it travels
– small pieces travel farther
– large pieces travel slower & lag behind
DNA
–

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Running a gel
fragments of DNA
separate out based
on size
cut DNA with restriction enzymes
1
2
Stain DNA
– ethidium bromide
binds to DNA
– fluoresces under UV
light
3
Virtual Lab 11
Restriction Enzyme Cleavage and Electrophoresis
Lab: Electrophoresis
DNA Fingerprinting
• Why is each person’s DNA pattern different?
– sections of “junk” DNA
• doesn’t code for proteins
• made up of repeated patterns
– CAT, GCC, and others
– each person may have different number of repeats
• many sites on our 23 chromosomes with
different repeat patterns
GCTTGTAACGGCCTCATCATCATTCGCCGGCCTACGCTT
CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGAA
Uses: Evolutionary relationships
• Comparing DNA samples from different
organisms to measure evolutionary
relationships
–
DNA
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turtle snake rat squirrel fruitfly
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Sequencing DNA: http://www.pbs.org/wgbh/nova/genome/sequ_flash.html