Download Genetic Engineering

Chapter 20:
Biotechnology
Essential Knowledge
– DNA, and in some
cases RNA, is the primary
source of heritable information
(20.1 & 20.2)
3.a.1
Focus of Chapter
An
introduction to the methods
and developments in:
Recombinant
DNA
Genetic Engineering
Biotechnology
Recombinant DNA
DNA
in which
genes from
different
sources are
linked
Ex: the
“green” mice
Genetic Engineering
The
direct manipulation of
genes for practical purposes
Ex: Using E. coli to produce
human insulin
Biotechnology
The
use of living organisms
or their components to
perform practical tasks
Ex: the use of bacteria to
digest oil spills
Plasmids
Small
circular piece of DNA
Carry many important traits
Used extensively in
biotechnology and recombinant
DNA
Serve as a “vehicle” for
transporting genes
Steps for Plasmid Use
1. Get the DNA for the trait
2. Insert DNA into the plasmid
3. Bacterial transformation
4. Identification of the new
trait
*Fig 20.4, page 399
Restrictive Enzymes
Cut
DNA at specific
nucleotide sequences called
“restriction sites”
Used to "cut and splice" DNA
Obtained from bacteria
Ex. EcoRI and Hind III
Insertion
Placing
foreign DNA into a
plasmid
Open plasmid with enzymes
to create “sticky ends”
Splice the new DNA and
plasmid together.
Transformation
Placing
the plasmid into a
bacterial cell
Methods
Temperature
shock & salt
treatment
Electric current
Injection
Identification
Screening
the altered cells
for the desired gene
Ex: Antibiotic sensitivity or
the expression of a “new”
trait (color, glowing etc.)
Example Applications
1. Insulin
2. Human Growth Hormone
3. Other Proteins
DNA Sources
1. Organism - use a section of
their chromosome
2. cDNA - created copy of DNA
(to avoid introns)
Organism DNA
Isolated
by restrictive
enzyme cuts
Separation by gel
electrophoresis
Pieces stored in a
genomic library
cDNA
Complementary
DNA
Artificial gene with no introns
Made from the mRNA for that
specific protein using
Reverse Transcriptase
DNA Sequencing:
Sanger Method
Uses
dideoxynucleotides
Build new DNA from single
strand DNA
Used to separate out
nucleotides
PCR Method
Polymerase
Chain Reaction
Used to make many copies of
a small segment of DNA
Quicker than Sanger method
RFLP Method
Restriction
Fragment Length
Polymorphism
Used for detecting minor
differences in DNA
Uses:
DNA
fingerprinting (crimes)
Pedigree studies (DNA markers)
Southern Blotting
method
Developed
by EM Southern in
1975
Used to compare fragments
from different genomes
Looks like a photograph
More permanent results
DNA Technology:
Applications
1. Basic Research
2. Medical
3. Forensics
4. Agricultural
Basic Research
1. DNA and protein studies
2. Evolution
3. Gene structure and control
mechanisms
Human Genome
Project (HGP)
15
year project which started
in 1990
Project was basically
completed in February 2000
HGP Goals
1. Linkage mapping of the
human genome.
2. Physical mapping of the
human genome.
3. Human genome sequence.
4. Genomes of other species.
Medical Uses
1. Diagnosis of Diseases
2. Gene Therapy
3. Vaccines
4. Pharmaceutical Products
Forensic Uses
DNA
fingerprints for crime
solving
DNA identification records
Agricultural Uses
1. Animals
Increased
milk production
Increased feed utilization
Increased meat production
Injecting DNA into egg
PharmAnimals
Agricultural Uses
2. Plants
Herbicide
resistance
Retard spoilage of fruits
Insect resistance
Nitrogen-Fixation ability
Future Of DNA
Technology
Cloning
of higher animals
Growth of replacement
tissues and organs
Gene therapy to correct DNA
defects
?
Gene Therapy
Summary
Recognize some of the basic strategies and
methods of gene manipulation and analysis.
 Identify representative examples of the
applications of DNA technology.
 Be prepared to discuss the implications of
genetically modified organisms (GMO’s) on
science, technology and society.
