what is transgenics

1. By Usman Arshad

2.  Biotechnology is
 The application of the technology to improve
the biological function of an organism
by
adding genes from another organisms
Transgenics

3.  Isolating genes
 Modifying genes so they function better
 Preparing genes to be inserted into a new species
 Developing transgenes
Genetic engineering is the basic tool set of biotechnology
Genetic engineering involves:

4.  Transgenic – an organism containing a
transgene introduced by technological (not
breeding) methods
Concept Based on the Term Transgene
Transgene – the genetically engineered gene added to a species

5.  To develop the organisms that express a “novel” trait
not normally found in the species
Extended shelf-life tomato (Flavr-Savr)
Herbicide resistant soybean (Roundup Ready)

6. 1. Study gene function and regulation
2. Generate new organismic tools for other fields of
research.
3. Cure genetic diseases.
4. Improve agriculture and related raw materials.
5. Generate new systems or sources for
bioengineered drugs (e.g., use plants instead of
animals or bacteria).

7. Insect resistant cotton – Bt toxin kills the
cotton boll worm
• transgene = Bt protein
Insect resistant corn – Bt toxin kills the
European corn borer
• transgene = Bt protein

8. Herbicide resistant crops
Now: soybean, corn, canola
Coming: sugarbeet, lettuce, strawberry
alfalfa, potato, wheat
• transgene = phosphinothricin-N-
acetyltransferase
Virus resistance - papya resistant to
papaya ringspot virus
• transgene = virus coat protein

9. Biotech chymosin; the enzyme used
to curdle milk products
• transgene = genetically engineered enzyme
bST; bovin somatotropin; used to increase
milk production
• transgene = genetically engineered enzyme

10. Sunflower – white mold resistance
transgene = oxalate oxidase from wheat
Golden Rice – increased Vitamin A content
(but not without controversy)
transgene = three pathway enzymes

11. Turfgrass – herbicide resistance;
slower growing --- reduced mowing
Bio Steel – spider silk expressed in goats; used to
make soft-body bullet proof vests (Nexia)

12. • Works like any vaccine
• A transgenic plant with a pathogen protein gene is developed
• Potato, banana, and tomato are targets
• Humans eat the plant
• The body produces antibodies against pathogen protein
• Humans are “immunized” against the pathogen
• Examples:
Diarrhea
Hepatitis B
Measles

13. Steps
1. Create transformation cassette
2. Introduce and select for transformants

14. Contains
1. Gene of interest
The coding region and its controlling elements
2. Selectable marker
Distinguishes transformed/untransformed plants
3. Insertion sequences
Aids Agrobacterium insertion

15.  Prepare tissue for transformation
 Tissue must be capable of developing into normal plants
• Leaf, germinating seed, immature embryos
 Introduce DNA
 Agrobacterium or gene gun
 Culture plant tissue
 Develop shoots
 Root the shoots
 Field test the plants
 Multiple sites, multiple years

16.  Transformation cassettes are developed in
the lab
 They are then introduced into a plant
 Two major delivery methods
Tissue culture
required to generate
transgenic plants
• Agrobacterium
• Gene Gun

20. Herbicide Resistance
Transgenics
Non-transgenics

21.  Consumer acceptence
 Flavr Savr tomatoes----poor quality

22. Bt cotton
Rice

23.  Important cash crop for Pakistan known as
“White Gold”
 Contribute to 8.2 percent of the value added in
agriculture and about 3.2 percent to GDP
 Fourth-largest cotton producer and the third
largest exporter of raw cotton

24.  High price of agriculture inputs
 Higher intensity of insects and pests attack,
 Shortage of good quality and varieties of seeds,
 Water deficiency
 Lack of advance technologies,
 Lack of awareness and agro-professionalism,
 Adulterations in pesticides, fertilizers and seeds

25.  Two major types of pests are damaging our cotton
crops
◦ Sucking
◦ Chewing
Easy to cure the sucking pests but
difficult to cure the chewing ones.
Bollworms known as “Sundies”
Cause major devastations
So overall both quality of lint and production of
cotton have declined substantially

26.  Bt gene introduction
 Bacillus thuringiensis---bacterium that is pathogenic
for a number of insect pests
 Lethal due to protein toxin it produces
 If that gene is introduced in plant genome then its
expression provides protection from pests.

27.  Bt cotton was widely planted first time in 1996 on large scale
 In Pakistan, PAEC in 1997
 In 2005 different varieties are introduced
◦ IR-FH-901
◦ IR-NIBGE-2
◦ IR-CIM-448 and
◦ IR-CIM-443
Bt Rice and Corn are under trilas in
china

28.  For the resistance of bacterial leaf blight.
 Rice varieties transgened
◦ Basmati -370
◦ DR - 82
◦ IR – 6
Gene:-
Xa21
Done by an Agrobacterium mediated transformation.

29.  All PCR positive transgenic plants
◦ DR – 82
◦ Basmati - 370
were resistant with lesion areas less than 5% of
the inoculated leaf area

30.  Genetically Modified (GM) food is as safe or even
safer than conventionally produced food
 GM foods represent a very minor, precise and known
change
 GM foods are subject to intense pre-market testing
 GM foods are subject to stringent regulatory oversight