1. Genetic Technology
Manipulating Genes

2. A. Genetic Engineering
Genetic engineering (AKA recombinant DNA technology) is faster & more reliable method of selecting certain trait in population
Artificial selection is humans breeding specific populations (usually domestic animals & crops) with certain traits – slow process
Natural selection is nature selecting specific populations with certain traits – very slow process

3. Genetic engineering involves cleaving (cutting out) DNA from one organism into smaller fragments & inserting desired gene into host DNA of same or different species
Desired gene
Host DNA

4. Also called recombinant DNA technology since DNA gets recombined to make one new one
If plants or animals contain foreign DNA from this technology, are called transgenic organisms or genetically modified organism (GMO)
Example is tobacco plant that contains glowing gene from firefly – plant glows!!

5. Example of Transgenic Organisms
Zebra Fish
Firefly Bioluminescence
Tobacco Plant
Caterpillar

6. 1. Cleave DNA 2. Make a vector B. Steps of Engineering
Making transgenic or GMO takes 3 steps:
1. cleave DNA – isolate DNA fragment
2. vector - attach DNA fragment to carrier
3. insertion - insert DNA into host organism
3. Insert into host
2. Make a vector
1. Cleave DNA

7. DNA Cleavage
Must isolate small parts of DNA (DNA can contain millions of base pairs
use special enzymes called restriction enzymes that cut both sides of dsDNA at specific areas of nucleotide sequence
depending on which way DNA is cut, get 2 different ends:
sticky end
blunt end

8. sticky end dsDNA is cut leaving some single strands
can only do that if there is a palindrome = letter order written same way backwards as forwards
ex: “mom” backwards is “mom” but with dsDNA, both sides are included
“GAATTC” on top side (forwards) and “CTTAAG” on bottom side (backwards)
A T C C A G G A A T T C C A A G C T C
T A G G T C C T T A A G G T T C G A G

9. restriction enzyme recognizes specific palindromes and will cut somewhere within there
ex: EcoRI recognizes GAATTC & will cut in b/t G – A on both sides leaving sticky ends ready to bond
A T C C A G G A A T T C C A A G C T C
T A G G T C C T T A A G G T T C G A G
A A T T C C A A G C T C
A T C C A G G G G T T C G A G
T A G G T C C T T A A
After Cleaving

10. TTAA and AATT sticky end have nothing to bond to, so if same restriction enzyme cuts DNA of organism and host’s organism, both sticky ends will match so bonding will be easier
Vector
Organism

11. Example of Sticky ends

12. blunt end DNA is cut all way through like with scissors
A T C C A G G A C T T C C A A G C T C
T A G G T C C T G A A G G T T C G A G
A T C C A G G A C T T C C A A G C T C
T A G G T C C T G A A G G T T C G A G
both ends are bonded with other bases so are blunt
After Cleaving

13. Examples of Restriction Enzymes

14. Attach to vector
Loose fragments of DNA need to be attached to vector (carrier) first
Two types of vectors:
Biological vector: bacteria plasmid or virus
Mechanical vector: micropipette or microscopic metal bullet

15. Since both DNA and vector were cleaved with same restriction enzyme, both ends will match
Join pieces using DNA ligase

16. Insertion into host
Recombined plasmid (or other vector) is inserted into host’s cell
When host replicates, inserted DNA also replicates producing more of that desired gene
bacterial plasmid can replicate every 20 min!

17. Bacterial plasmid Virus Inserts plasmid into bacteria’s cytoplasm
Injects DNA directly into host’s DNA
Process called transduction

18. Clone: genetically identical copies of original
Plasmid can replicate 500 times per cell, and each clone replicates 500 times… and so on
Clone: genetically identical copies of original
Dolly ( )
The first ever cloned animal

19. Cloning

20. can also replicate DNA segments by using Polymerase Chain Reaction (PCR)
dsDNA strands are separated (unzipped) by heat
special heat-resistant enzymes replicate DNA
important advancement technique used to match DNA with very little DNA to begin with
Don’t need much DNA from crime scenes

21. PCR Technique

22. Example of Recombinant DNA

23. C. Uses for Genetic Engineering
recombinant DNA (genetic engineering) is currently useful in many areas of life
Industry
Medicine
Agriculture

24. Industry
clothing: bacteria E. coli are transgenic with DNA to make indigo dye
indigo dye in nature is VERY expensive, so can make blue jeans cheaply
food: making corn that has high protein content (corn is mostly carbohydrate)
fuel: use corn husks to make fuel for cars
sewage: clean water using bacteria

25. Medicine
hormone: can produce human growth hormone (hGH) to treat people with growth disorders (Achondroplasia, Turner syndrome)
medicine: produce human insulin (formerly bovine/cow) with bacterial plasmids
diseases: transgenic sheep are produced that produce Factor VIII protein for hemophiliacs
Vaccines: remove virus’ dangerous genes

26. Agriculture making more/bigger/healthier/fresher food
Crops resistant to viruses and insects
canola plants make more canola oil
peanuts & soybeans that don’t cause allergic reactions
corn that can grow with very little water (survive drought)

27. D. The Human Genome Project
International effort started in1990, Human Genome Project (HGP) was organized to completely map and sequence human genome
complete sequence of nucleotides (3.2 billion) in human DNA (completed 2000).
Complete map of 20,000 genes (2006) on 23 sets of chromosomes

28. Human Genome Project
Leaders of the Genome Project (Dr. Landers and Dr. Collins

29. How did they do that?
1. How did they find out that genes U-Z are on chromosome set #2 and not on set #8?
2. How do we know gene N is next to M and O and not somewhere else?
ANSWER: Linkage Maps A B C D A B C D
QRS
QRS U V W X Y Z U V W X Y Z
Set# 2
Set# 8
LMNOP
LMNOP

30. Linkage Map
Linkage map: genetic map that shows relative locations of genes on a chromosome
Found locations of genes on specific chromosomes, but didn’t know the order
Gene M is on chromosome 11
Where on chromosome 11 is gene M?
Can find RELATIVE order of genes from a linkage map

31. Linkage Map
Chromosome 11
Chromosome M

32. Using PCR, can make millions of copies of DNA fragments to find patterns in certain genes
Use genetic markers to trace inheritance of genes, which shows us where that gene is located relative to the others

33. Father has genes M & HD
Mother does not
Out of 5 kids, 3 inherited M, and of those 3, 2 also got HD
M & HD are close to each other

34. Gel Electrophoresis
Process of separating DNA fragments to compare sizes and therefore similarities
Electricity is sent through gel containing DNA fragments
DNA pieces will migrate toward bottom
Smaller pieces will “run” faster
Larger pieces will be stuck toward top
large
small

36. Genetic Markers

37. Paternity Tests
Results: D2 not Dad’s
Results: S2 adopted

38. How did they sequence it?
sequencing human genome compares DNA fragments to each other
pieces that overlap are pieced together
All these fragments came from cleaving DNA into little workable pieces
ABCD
NOPQ
DEFGHIJ
ABCDEFGHIJKLMNOPQRSTUVWXYZ
IJKLMNOP
RSTUVWX
WXYZ
BCD
LMNOPQRS
By lining up pieces that overlap, can get entire sequence

39. E. Applications of HGP
Diagnosing genetic disorders – individuals find out if they are carrying gene for specific disease
Can be done for fetuses using epithelial cells (from amniotic fluid)
Dilemma – do YOU want to know if you have gene for cancer or heart disease?
Pros: can alter lifestyle NOW to help prevent cancer or heart disease from coming
Cons: always in fear about what may or may not happen

40. Gene therapy – inserting normal genes into human cells to correct genetic disorder
Cystic fibrosis, sickle-cell anemia, hemophilia, AIDS, cancer, heart disease are all being studied as genetic diseases in which gene therapy may work

41. Gene Therapy

42. Gene Therapy

43. DNA fingerprinting – compare unknown DNA to known DNA to find out if they match
DNA cut by restriction enzymes would show same sizes each time (same palindrome sequence)
Called restriction fragment length polymorphisms (RFLPs)
Solve crimes
Maternity/paternity
Known
UNKnown A B

44. DNA Fingerprinting

45. DNA Fingerprinting

46. Paternity Tests
Results: D2 not Dad’s
Results: S2 adopted