1. DNA Technology

2. The process of manipulating genes for practical purposes.
Genetic Engineering
The process of manipulating genes for practical purposes.
Because all DNA has the same basic structure, we can cut and paste genes from one organism into the chromosome of another organism.

3. Recombinant DNA Vector Gene of Interest
DNA made from two or more different organisms
(Connecting DNA from different sources)
Gene of Interest
The gene to be inserted
(Codes for the trait we want expressed)
Vector
The DNA into which we will insert the gene of interest.
*Bacterial DNA makes a great vector*

4. Steps in Genetic Engineering
Step 1: Cut Gene of Interest & Vector
with restriction enzymes.
gene from other organism
transformed bacteria
recombinant plasmid
vector
Bacterial
DNA
cut DNA +
glue DNA

5. How Do We Cut DNA? Restiction Enzymes
Enzymes that cut DNA in specific locations
“Blunt” ends
CANNOT be glued to another piece of DNA.
“Sticky” ends
CAN be glued to another piece of DNA.

6. Why do we need “Sticky” ends?
Sticky ends make it possible to
“glue” cut ends together.
MUST cut Gene of interest & Vector plasmid with the SAME restriction enzyme!!
MUST have
Complimentary Sticky ends!

7. How do we “Glue” sticky ends together?
Step 2: Connect DNA fragments together
How do we “Glue” sticky ends together?
DNA Ligase
An enzyme used to connect sticky ends of DNA fragments

8. How do we get more of these transformed bacteria?
Single Transformed Bacteria
Feed them and they will reproduce!
Binary Fission
Copy DNA and split = “Cloning”
Culture Bacteria
Harvest (purify) protein
Gene Cloning

9. Word Processing Cut, Paste, Copy, Find…
So, Transformation is like:
Word Processing Cut, Paste, Copy, Find…
Cut
Restriction enzymes
Paste
Ligase
Copy
Plasmid replication
Binary Fission
Bacterial Transformation
Change the meaning of the message. 9

10. Many Uses of Restriction Enzymes…
Now that we can cut DNA…
We can COMPARE it!
Why?
Forensics
Medical diagnostics
Paternity
Evolutionary relationships
and more… 10

11. “Swimming through Jello”
Comparing DNA
Gel Electrophoresis
A method of separating DNA fragments by size using an electrical field.
DNA is negatively charged so in an electrical field it moves toward the positive side
Small pieces travel faster/farther than larger pieces.
DNA         – +
“Swimming through Jello” 11

12. DNA & Restriction enzyme Restriction Fragments
Gel Electrophoresis:
DNA & Restriction enzyme
Restriction Fragments
negative -
Completed gel
wells
Longer fragments
power
source
gel
Shorter fragments
Who’s going to
win the race? +
Electrical current
positive 12

13. DNA Fingerprint
A pattern of dark bands on photographic film made when an individual’s DNA restriction fragments are separated by gel electrophoresis, probed, and then exposed to an X-ray film.
Because each individual’s DNA is unique, each person has a unique DNA fingerprint

14. DNA Fingerprint Uses: Forensics
Comparing DNA sample from crime scene with suspects & victim
Suspects
You’re Under
Arrest!
Crime scene sample S1 S2 S3 V –
DNA  + 14

15. DNA Fingerprint Uses: Paternity Cases
Who’s the father? –
Mom F1 F2
child
DNA  + 15

16. PCR Process used to repeatedly copy the same piece of DNA many times.
Helpful in magnifying DNA from:
Crime scenes
Fossil remains
PCR Animation

17. Human Genome Project 3.2 billion base pairs in the human genome
Only 1-1.5% codes for proteins
Only about 30,000 to 40,000 genes

18. Why would we want to do this?
Genetic Engineering
Why would we want to do this?
To Create Drugs & Vaccines:
Create organisms (Animals or bacteria) that produce human proteins
Sheep that secrete a human blood protein
in their milk that can be used to slow lung
damage in cystic fibrosis patients.
Bacteria that produce:
Factor VIII-protein that promotes blood
clotting to treat Hemophilia
Growth hormones
Production of human insulin by bacteria
To Grow Organs for transplantation:
Mice that grow a human ear which can be used for transplant

19. To create better agricultural products:
Genetic Engineering
Why would we want to do this?
To create better agricultural products:
Delayed ripening & resistance to spoilage
Anti-softening tomatoes
Protect crops from insects: BT corn
Corn produces a bacterial toxin that
kills corn borer (caterpillar pest of corn)
Herbicide resistance: Cotton
Bacterial gene resistant to weed-killing herbicides
Improve quality of food: Golden rice
Rice producing vitamin A improves nutritional value

20. Animal Cloning
Dolly
1st Cloned Animal 1996

21. Problems with Cloning Few survive Fatally oversized
Problems in development
Why does it Fail?