Transcript No Slide Title

DNA extraction
recap
Safety point
• Spill phenol on bare feet (flip flops!) goodbye skin
• Spill phenol on shoes – maybe stained
shoes
• Spill phenol on bare legs (shorts) goodbye skin
• Spill phenol on pants – stained pants
Calculation of DNA concentration
1) Measure UV absorption spectrum
Calculation of DNA concentration
• Absorbance coefficient for dsDNA at 260nm =
50
• So DNA with an absorbance of 1 at 260nm =
50ug/ml (or 50 ng/ul)
• We diluted your DNA 1 in 100
• Multiply the A260 by 50 to get concentration
of diluted sample
• Then multiply by 100 to get concentration of
your sample
DNA extraction from plants
• Smush (“homogenize”) the cells
• Dissolve membranes and solublize DNA
in a detergent buffer.
• Remove solids with centrifugation
• Remove proteins with KOAc
• Remove proteins with phenol extraction
• Precipitate DNA with alcohol
DNA extraction issues
• Homogenization
- has to be “just right”
• RNA
• Hydrodynamic
shearing
- treat it gently
Agricultural biotechnology
A major application of genetic
engineering
Plant genetic transformation
1) Need to engineer genes into a “vector”
(recombinant DNA or genetic
engineering)
2) Need to get vector into plant cells (gene
delivery)
3) Need to grow whole plant from a single
cell (regeneration)
Gene Delivery
Agrobacterium
Particle gun
Introduction of
the gfp gene into
different target
tissues
Petunia petal - cells
Soybean seed
Wheat callus - cells
Plant Recovery
Starting Material
Immature seeds
Germination
Soybean
Regeneration
Development
Induction
Proliferation
Xmas Cactus
Poplar
Cotton
Soybean
Fern
Ohio Buckeye
Biotech traits
• “Input traits”
• Make product easier or cheaper to produce
• Herbicide resistance (e.g. Roundup Ready, Liberty Link).
Labor saving, can reduce overall herbicide usage.
• Insect resistance (e.g. many Bt products). Reduces or
eliminates pesticide usage.
• “Output traits”
• Add quality to product.
• Storage properties (e.g. Flavr Savr). Longer lasting fruit,
easier to transport.
• Composition (e.g. pharming, oil / protein).
Bt Corn Reduces:
Insecticide
Application
Mycotoxin
Production
Monarch larvae on
Butterfly weed
X
Acreage of
GMO
Varieties
Acreage of GMO Varieties
Public Support Varies for Different
Applications of Biotechnology
(Includes ALL Countries – N = 35,000)
85
New Human Medicines
Crops to Produce Plastics
74
Bacteria to Clean Waste
73
71
Crops with Fewer Chems
68
More Nutritious Crops
55
GM Feed (Healthier Meat)
42
Clone Animals (Medicine)
35
Increase Animal Productivity
0
10
20
30
40
50
60
70
80
90
100
(Percent Agreement)
Source: Thomas Hoban, North Carolina State University
The Benefits of Using Biotechnology
are Greater than the Risks
(35,000 Consumers from 35 Countries)
66
United States
7
27
Asia (Average)
60
15
25
Latin/South Amer (Ave)
59
16
25
55
Canada
8
44
Australia
14
40
Russia
0%
20%
42
37
38
Europe (Average)
37
23
18
40%
Agree
Not Sure
44
60%
Disagree
80%
100%
The Benefits of Using Biotechnology
are Greater than the Risks
(European Consumers)
55
Netherlands
Great Britain
42
Germany
41
8
11
49
25
34
Italy
47
10
39
Spain
37
36
18
48
France
22
24
54
Greece
22
24
54
0%
20%
40%
Agree
Not Sure
60%
Disagree
80%
100%
Willing to Buy GM Food if More Nutritious
(Net = Continue – Not Continue)
China
66
56
India
Brazil
31
25
USA
Canada
21
Japan
1
Mexico
1
Germany
-5
Australia
-5
Great Britain
-7
-10
0
10
20
30
40
Percent Response
50
60
70
Perceptions of safety improved when US
consumers learn that biotech foods have been
in the stores.
Do you think genetically
modified foods are basically
safe, basically unsafe, or don’t
you have an opinion on this?
Now, as you know, more than
half of products in the grocery
store are produced using some
form of biotechnology or genetic
modification. Knowing this, do
you think genetically modified
foods are basically safe, basically
unsafe, or don’t you have an
opinion on this?
January 2001
25%
21%
Unsafe
46%
31%
29%
48%
Not sure
Safe
Source: Pew Initiative on Food and Biotechnology
“By Eating a Genetically Modified Fruit, a
Person’s Genes Could also Be Changed”
Canada
62
United States
61
18
30
29
Austria
32
25
38
23
32
30
58
Italy
24
74
Netherlands
20
60
0
20
15
30
40
60
10
18
25
55
United Kingdom
18
16
62
Sweden
Switzerland
9
39
52
France
Germany
20
15
80
100
Percent Response
False (Correct)
Don't Know
True
1996 - 1998
Source: Thomas Hoban, North Carolina State University
“Ordinary Tomatoes Do Not Contain Genes,
while Genetically Modified Ones Do”
52
Canada
45
United States
22
32
France
36
Italy
35
44
29
20
44
44
21
51
Netherlands
27
46
48
Switzerland
40
United Kingdom
0
10
39
Germany
Sweden
15
45
34
Austria
1996 - 1998
33
20
22
24
30
21
31
38
40
22
60
80
Percent Response
False (Correct)
Don't Know
True
100
Thanks
• Thanks to Monsanto for making MTU
available
• Thanks to John Finer for biotech
images.