CREATING GENETIC
RESISTANCE
THROUGH GENETIC
ENGINEERING
By
DANIEL OKYERE
MPHIL PLANT BREEDING
CS 555 PEST MANAGEMENT - ASSIGNMENT
INDEX NUMBER-PG4993818
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What Is Genetic Engineering?
• Directly altering/ manipulating structure and characteristic
of the gene so as to manipulate biological processes and/ or
organisms for the benefit of humankind
• Also known as recombinant DNA technology or gene
manipulation or gene cloning, means altering the genes in a
living organism to produce a Genetically Modified Organism
(GMO) with a new genotype
• Various kinds of genetic modification are possible:
• inserting a foreign gene from one species into another, forming a
transgenic organism;
• altering an existing gene so that its product is changed.
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BASIC STEPS OF GENE
MANIPULATION
1. A fragment of DNA, containing the gene to be cloned, is
inserted into a circular DNA molecule called a vector, to
produce a recombinant DNA or (rDNA)
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BASIC STEPS OF GENE
MANIPULATION
2. The vector transports the gene into a host cell, which is usually a
bacterium
3. Within the host cell the vector multiplies, producing the numerous
identical copies not only of itself but also of the gene it carries
4. When the host cell divides, copies of the rDNA are passed to the
progeny
5. After several cell divisions, a colony of identical host cells (clone)
is produced.
Each cell in the clone contains one or more copy of rDNA
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The process of genetic engineering
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TOOLS OF GENETIC
ENGINEERING
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1. Resctriction enzymes
• DNA cutting enzymes (molecular scissors)
• Restriction endonucleases cuts DNA at a specific site
defined by a sequence of bases in the DNA (recog.site)
forming “sticky ends”
• Palindromic sites
Eg. BamHI cuts 5' GGATCC 3'
3' CCTAGG5’
HaeIII cuts 5' GGCC 3'
3' CCGG 5'
• several hundred endonucleases have been extracted
from bacteria and many are used in recombinant DNA
research. eg EcoR1,Hind III, HaeIII, TaqA1, Sau3A
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2. VECTORS
• Carrier of DNA (can transfers the rDNA into the host
cell)
• Should be small ( <10kb)
• Should have an origin of replication
• Could replicate in the host cell
• It may be plasmid, viral genome or yeast
chromosome
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Plasmids
• Molecules of DNA that are found in bacteria
• Act as a system to transfer genetic material to other
bacteria, allowing those to express the transmitted
genes.
• small (a few thousand base pairs) & circular
• usually carry only one or a few genes
• can survive in normally toxic concentrations of
antibiotics
• Eg. pBR322, Ti plasmid, pUC19, BAC, etc.
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METHODS OF INSERTING
“GENE OF INTEREST”
INTO THE HOST CELL
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DNA can be inserted into cell by:
• Electroporation
– Cells with cell wall need to be
converted to protoplasts
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DNA can be inserted into cell by:
• Gene gun
– DNA is coated on tiny gold
beads and propelled into
the cells
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DNA can be inserted into cells by:
• Microinjection
– Glass pipette
punctures the cell
membrane & inserts
the DNA
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APPLICATIONS
OF
GENETIC ENGINEERING
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• To increase crop resistance to disease or climate.
• To test and screen for genetically inherited
diseases.
• To cure disease by altering the genes.
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Genetic Engineering
&
The Production
Of
Transgenic Organism
(GMO)
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• The best bullet
proof vest ever!
• Strong as steel
cables
• And much
more…
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Corn
• 25 percent of
corn is
genetically
modified
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Insect Resistant
• The bulk of both
soy beans and corn
that is genetically
modified is
modified to have a
natural insecticide
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Bt - COTTON
• Bt cotton – pest and insect
resistant cotton
• Containing cry1Ac gene form
Bacillus thuringiensis
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Ethics Involving Genetic
Engineering
• Ethical issues concerning human beings and animals
- Are we playing God?
- Religions beliefs
- Creates new viruses
- Designer Babies
• Genetic Engineering and Plants
- Effects on our Environment
- Long run effects on environment
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We wish you a merry Christmas we wish you a merry Christmas
We wish you a merry Christmas and a happy new year
&
GOD BLESS YOU ALL
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