DNA/GENE TECHNOLOGY

1
DNA/GENE TECHNOLOGY

• Chapter 9

2
Types of Genetic Engineering

• Selective Breeding
• GMOs
• Gene Sequencing
• Gene Cloning/Pharmaceutical Production
• DNA Fingerprinting
• Transgenic Organisms
• Therapeutic Cloning/Stem Cells
• Reproductive Cloning
• Gene Therapy
• Human Genome Project

3
Assignment 1 Genetic Engineering/Technology
Article Summary due Friday

• Find ONE article from Mrs. Holdens MCHS teacher
  page (handouts)
• Read
• Include
• A summary the article.
• Which technology/technologies are discussed in
  the article?
• What are some ethical/moral issues with this type
  of technology?

4
Engineering vs. Technology

• Genetic Engineering
• The process and outcome of making changes in the
  DNA code of living organisms
• Genetic Technology
• The tools and instruments used and developed for
  the process of manipulating genes

5
Selective breeding

• Produces organisms with desired traits
• 2 Types Inbreeding Hybrids
• What traits might breeders want to select for in
  these organisms?

6
Inbreeding

• Mating of closely related individuals
• Ensures that offspring remain homozygous for most
  traits
• Keeps wanted traits in the breed
• Keeps out un-wanted traits

Pure-Bred (inbred) Bulldog
Inbred Weimeraner Dog
7
Inbreeding

• Does have a high risk of offspring receiving 2
  HARMFUL recessive alleles that were present in
  the family line
• Which means???
• Causes mutations that ALREADY exist to pair at a
  higher frequency

8
Hybrids

• Usually produce larger, stronger organisms
• AND VARIATION!
• Mixing dominant recessive keeps out harmful
  recessive phenotypes
• ESPECIALLY IN PLANTS!

9
HybridsDogs and Ligers and Geep oh my!

• Hybridization Mating of slightly dissimilar
  organisms to produce desired combination
• Must have same chromosome number, similar
  structure
• Liger

Geep Hybrid of Goat and Sheep
10
Cloning
11
Types of cloning

• Gene cloning
• Inserting just one gene into org to copy
• Therapeutic cloning
• Stem cells ? new cells/organs
• Reproductive cloning
• Creating an entire organism

12
Therapeutic Cloning/Stem Cells

• Stem cells undifferentiated cells
• Can develop into any type of cell in body
• Embryonic most potential for success
• But regulated by law
• Bone marrow/Spinal some potential for success

13
Possible clone use

• Cloning new stem cells to repair tissues

14
Stem Cells are Found in the Adult, but the Most
Promising Types of Stem Cells for Therapy are
Embryonic Stem Cells
15
Therapeutic Cloning/Stem Cells
Therapeutic cloning- cloning of specific
cells/tissues/organs not whole organism
16
Some Thorny Ethical Questions
Are these masses of cells a human?
Is it ethical to harvest embryonic stem cells
from the extra embryos created during in vitro
fertilization?
17
Gene Cloning

• Cloning a single GENE in an organism
• Organism copies gene through replication
• Produces proteins

18
Reproductive Cloning
19
Reproductive Cloning

• Making an identical organisms genetically
  speaking
• Steps
• 1. Take DNA (nucleus) from existing org.
• 2. Take egg cell and replace its nucleus (DNA)
  with existing org. DNA (nucleus)
• 3. Allow egg cell to develop into offspring
• 4. Offspring will have same DNA as existing
  organism
• Why should we clone?
• Food industry?
• Endangered species?
• Problems/Ethics?

Dolly I and Dolly II her clone
20
Reproductive Cloning - Pet Cloning?
University of Texas 2002 Success Rate of 1/87
embryos Significantly, Carbon Copy is not a
phenotypic carbon copy of the animal she was
cloned from Environmental factors and proteome
interactions cause phenotypic differences Nature
vs. Nurture argument FYI cost 3.7 million
21
Clones
22
Possible clone use

• Clone successful plants

23
Transgenic organisms

• Organisms with genes from other species
• Ex Mice with jellyfish gene will glow!!!
• Benefits of transgenics
• Gene function determination
• Medical studies, drug trials
• Creation of medical proteins/drugs
• Hybrid organisms/GMOs
• EX Human chemotherapy drug in chickens

24
Transgenic Organisms
25
Creating Recombinant DNA

• 1. Cut (cleave) DNA from one organism with a
  restriction enzyme
• 2. Insert (splice) the wanted genes (DNA) from
  another organism (Fig 13.4)
• RESULT
• RECOMBINANT DNA TRANSGENIC ORGANISM
• Usually done on plasmid DNA (bacterial)
  circular DNA

26
What is recombinant DNA?
27
Ex Transgenic Bacteria AKA Bacterial
Transformation

• RAG-1 contains transgenic enzyme which breaks
  down oil used in Gulf Oil Spill
• Produce human proteins
• Insulin
• Human Growth Hormone
• Produce antibiotics

28
Genetically Modified Organisms GMOs

• Altering the genetics of plants or animals for
  human benefit
• One of the first was Bt cotton
• Bacterial gene from Bacillus thuringiensis was
  put in cotton
• Made it toxic to insects
• Specifically the Boll Weevil

GMO Cotton (contains a bacterial gene for pest
resistance) 80 of all cotton
Standard Cotton
29
Genetically Modified OrganismsGMOs

• Altering the genetics of plants and animals for
  human consumption
• Polyploidy chemicals disrupt meiosis bigger
  fruit or seedless fruit

30
Genetically Modified OrganismsGMOs
31
Transgenic vs. Clone
Transgenic Organisms have genes inserted from
another organism Cloned Organisms have the exact
same DNA as another organism
Tobacco Plant with firefly gene
Dolly the cloned sheep
32
Gene Therapy

• Vectors-carry DNA from one source to another.
  Useful in gene therapy and making recombinant DNA
• A virus is often used
• Knock out the viral DNA and add desired gene to
  infect patient

33
Gene Therapy

• Restriction enzymes cut out normal gene from
  genome sample
• Take out viral DNA and add normal human gene to
  virus
• Viral vector infects patient with normal gene
  to replace mutated one
• Normal gene inserts into patients DNA and now
  produces proper protein/trait
• Ex normal CF gene being infected into a cystic
  fibrosis patient

34
Manipulating DNA
35
YOUR TURN!

• You will complete the Study Guide pages for
• 13.1 REVIEW of today
• 13.2 Pre-view of tomorrow!

36
What if there isnt enough DNA in the sample?

• Tiny amounts of DNA can be amplified by a
  technique called PCR (polymerase chain reaction)

37
PCRMaking enough DNA to read

• Three step amplification cycle
• Cycles of heating and cooling
• Causes DNA to separate (DENATURE) and then come
  back together (ANNEAL)
• Use DNA Polymerase
• Generates MORE DNA a certain size of DNA fragment
  (from one sample)

PCR
38
(No Transcript)
39
Now that we have enough DNA

• Whats next?

40
Inside storyPage 354
41
CUTTING DNARestriction Enzyme

• We will use TA-ase, an imaginary enyzme, to cut
  our DNA
• Sample DNA strand
• CTGGCTAGGCTACCATGCCCGTAAAT

Restriction Enzymes
42
Restriction Enzymes
43
CUTTING THE DNARestriction Enzyme

• We will use TA-ase, an imaginary enyzme, to cut
  our DNA
• Sample DNA strand CTGGCTAGGCTACCATGCCCGTAAAT

CTGGCTA GGCTA CCATGCCCGTA AAT
44
SEPARATING THE DNA Gel Electrophoresis

• Electricity separates fragments by size in a gel
• Largest fragment travels least
• Smallest the most

Gel Electrophoresis
45

• DNA is slightly (-), thus it will move towards ()

46
(No Transcript)
47
Gel Electrophoresis
48
Here are our DNA fragments

• Which one will travel fast and far?
• WHY?
• Which one will travel slow and short?
• WHY?

CTGGCTA GGCTA CCATGCCCGTA AAT
1
3
4
2
49
SEPARATING THE DNA Gel Electrophoresis

• CCATGCCCGTA
• CTGGCTA
• GGCTA
• AAT

50
Inside storyPage 354

• How many samples were tested in this example?

51
SEPARATING THE DNA Gel ElectrophoresisRESULTSDNA
Fingerprint

• Can be used to ID persons
• Very effective means of
• Criminal identification exclusion
• Paternity cases
• Missing persons
• Entire DNA is not used, only portions known to
  differ from individual to individual
• Gel is sometimes called an autoradiograph or
  autorad

M Marker (control) DNA
52
DNA FINGERPRINTTHE LAB BASICS (A SUMMARY)

• PCR to increase the amount of DNA
• Restriction enzymes to cut the DNA into
  different sized fragments
• Gel Electrophoresis to separate fragments
  according to size
• CONCLUSION Try to match fragments from
  different samples

53
STEP 4 READINGHow do you read a DNA
fingerprint?
Victims DNA finger print
54
STEP 4 READINGHow do you read a DNA
fingerprint?
A
B
C
D
E
Victims DNA finger print
Which sample is a match?,
55
STEP 4 READINGHow do you read a DNA
fingerprint?
A
B
C
D
E
Victims DNA finger print
Which sample is a match?,
56
STEP 4 READINGHow do you read a DNA
fingerprint?
C
Victims DNA finger print
Which sample is a match?,
57
Using DNA evidence
58
ANALYZING DNA SAMPLES

• Lets try some

59
DNA FINGERPRINTING

• Comparing different samples of DNA

60
Paternity Testing

• Not just matching evidence to suspect

61
(No Transcript)
62
Gene Sequencing How do we know what a gene does?

• Gene cloning (in a bacterium)? protein synthesis
  ? analysis of amino acid sequence
• Gene knockout in lab animals
• Comparative sequences in people with
  disease/without

63
Gene Sequencing How do we know what the DNA is?

• Take gene cut by restriction enzymes
• Put gene into bacteria/rat to see what protein
  does
• Use florescent DNA probes to bind to
  complementary sequences
• Ex Glowing ACT DNA probe would attach to TGA DNA
  id that sequence

64
Human Genome Project
65
Human Genome Project

• Linkage map
• Location of genes on a chromosome
• Sequencing
• Entire human genome was completed in 2003
• HUMAN GENOME PROJECT
• 30,000 plus genes
• Applications
• Diagnosis of disorders
• Gene therapy

66
Huntingtons Disease Pedigree

• An application of the Human Genome Project
• Sequencing the Human Genome has allowed us to
  genetically test for genes causing diseases
• Huntingtons is caused by a DOMINANT mutation on
  chromosome 4 which has an increased number CAG
  DNA triplet repeats compared to the normal allele