Download CH 13 Gene Technoogy PPT

GENE TECHNOLOGY
Chapter 13
Human Genome

Sequencing of the human genome was completed by
2007
 Create
a map showing where genes are located on
human chromosomes


DNA sequencing has depended on advances in
technology, starting with making recombinant DNA
In recombinant DNA, nucleotide sequences from two
different sources, often two species, are combined in
vitro into the same DNA molecule
Using Restriction Enzymes to Make
Recombinant DNA




Bacterial restriction enzymes cut DNA molecules at
specific DNA sequences called restriction sites
A restriction enzyme usually makes many cuts, yielding
restriction fragments
The most useful restriction enzymes cut DNA in a
staggered way, producing fragments with “sticky
ends” that bond with complementary sticky ends of
other fragments
DNA ligase is an enzyme that seals the bonds
between restriction fragments
Fig. 20-2a
Cell containing gene
of interest
Bacterium
1 Gene inserted into
plasmid
Bacterial
chromosome
Plasmid
Recombinant
DNA (plasmid)
Gene of
interest
2
2 Plasmid put into
bacterial cell
Recombinant
bacterium
DNA of
chromosome
Fig. 20-2b
Recombinant
bacterium
3 Host cell grown in culture
to form a clone of cells
containing the “cloned”
gene of interest
Protein expressed
by gene of interest
Gene of
Interest
Copies of gene
Protein harvested
4 Basic research and
Basic
research
on gene
Gene for pest
resistance inserted
into plants
various applications
Gene used to alter
bacteria for cleaning
up toxic waste
Protein dissolves
blood clots in heart
attack therapy
Basic
research
on protein
Human growth hormone treats stunted
growth
Fig. 20-2
Cell containing gene
of interest
Bacterium
1 Gene inserted into
plasmid
Bacterial
chromosome


Recombinant
DNA (plasmid)
Being able to
genetically
engineer
bacteria for
crops help
keep cost low.
Growing nonvirulent
bacteria to
clean oil spills
is cost
effective and
a safer choice
for our
environment.
Plasmid
Gene of
interest
DNA of
chromosome
2 Plasmid put into
bacterial cell

Recombinant
bacterium
3 Host cell grown in culture
to form a clone of cells
containing the “cloned”
gene of interest
Gene of
Interest
Protein expressed
by gene of interest
Copies of gene
Basic
Protein harvested
4 Basic research and
various applications
research
on gene
Gene for pest
resistance inserted
into plants
Gene used to alter
bacteria for cleaning
up toxic waste
Protein dissolves
blood clots in heart
attack therapy
Basic
research
on protein
Human growth hormone treats stunted
growth
Genetically
engineered
proteins could
mean less
invasive
procedures.
An alternative
to surgery.
Fig. 20-3-1
Restriction site
DNA
1
5
3
3
5
Restriction enzyme
cuts sugar-phosphate
backbones.
Sticky end
Fig. 20-3-2
Restriction site
DNA
1
5
3
3
5
Restriction enzyme
cuts sugar-phosphate
backbones.
Sticky end
2
DNA fragment added
from another molecule
cut by same enzyme.
Base pairing occurs.
One possible combination
Fig. 20-3-3
Restriction site
DNA
1
5
3
3
5
Restriction enzyme
cuts sugar-phosphate
backbones.
Sticky end
2
DNA fragment added
from another molecule
cut by same enzyme.
Base pairing occurs.
One possible combination
3
DNA ligase
seals strands.
Recombinant DNA molecule
Animation
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Methods for making recombinant DNA are
central to genetic engineering, the direct
manipulation of genes for practical purposes
DNA technology has revolutionized
biotechnology, the manipulation of organisms
or their genetic components to make useful
products
DNA Technology


An example of DNA technology is the microarray, a
measurement of gene expression of thousands of
different genes. This shows which genes are active in
all cells.
Another example of DNA technology is Gel
Electrophresis
Fig. 20-1
Gel Electrophoresis

Separates nucleic
acids or proteins
according to size
(density) and
charge.
DNA cloning

To work directly with specific genes, scientists
prepare gene-sized pieces of DNA in identical
copies, a process called DNA cloning
 DNA
cloning yields multiple copies of a gene or other
DNA segments.
DNA Cloning and Its Applications: A
Preview



Most methods for cloning pieces of DNA in the
laboratory share general features, such as the use of
bacteria and their plasmids
Plasmids are small circular extra-chromosomal DNA
molecules that replicate separately (autonomously)
from the bacterial chromosome. They are often used
as vectors in genetic engineering.
Cloned genes are useful for making copies of a
particular gene and producing a protein product




Gene cloning involves using bacteria to make
multiple copies of a gene
Foreign DNA is inserted into a plasmid, and the
recombinant plasmid is inserted into a bacterial cell
Reproduction in the bacterial cell results in cloning of
the plasmid including the foreign DNA
This results in the production of multiple copies of a
single gene
Cloning a Eukaryotic Gene in a
Bacterial Plasmid


In gene cloning, the original plasmid is called a
cloning vector
A cloning vector is a DNA molecule that can carry
foreign DNA into a host cell and replicate there
Animation
Please note that due to differing operating
systems, some animations will not appear
until the presentation is viewed in
Presentation Mode (Slide Show view). You
may see blank slides in the “Normal” or
“Slide Sorter” views. All animations will
appear after viewing in Presentation Mode
and playing each animation. Most
animations will require the latest version of
the Flash Player, which is available at
http://get.adobe.com/flashplayer.
Animation
Please note that due to differing operating
systems, some animations will not appear
until the presentation is viewed in
Presentation Mode (Slide Show view). You
may see blank slides in the “Normal” or
“Slide Sorter” views. All animations will
appear after viewing in Presentation Mode
and playing each animation. Most
animations will require the latest version of
the Flash Player, which is available at
http://get.adobe.com/flashplayer.
Amplifying DNA in Vitro: The Polymerase
Chain Reaction (PCR)


The polymerase chain reaction, PCR, can produce
many copies of a specific target segment of DNA
know as VNTR’s (specific DNA code repeats unique
to an individual). PCR and DNA Replication require
the same ingredients to make a new strand
(Helicase, DNA polymerase.)
A three-step cycle—heating, cooling, and
replication—brings about a chain reaction that
produces an exponentially growing population of
identical DNA molecules
Fig. 20-8a
5
TECHNIQUE
3
Target
sequence
Genomic DNA
3
5
Fig. 20-8b
1 Denaturation
5
3
3
5
2 Annealing
Cycle 1
yields
2
molecules
Primers
3 Extension
New
nucleotides
Fig. 20-8c
Cycle 2
yields
4
molecules
Fig. 20-8d
Cycle 3
yields 8
molecules;
2 molecules
(in white
boxes)
match target
sequence
Fig. 20-8
5
TECHNIQUE
3
Target
sequence
3
Genomic DNA
1 Denaturation
5
5
3
3
5
2 Annealing
Cycle 1
yields
2
molecules
Primers
3 Extension
New
nucleotides
Cycle 2
yields
4
molecules
Cycle 3
yields 8
molecules;
2 molecules
(in white
boxes)
match target
sequence
Animation
Please note that due to differing operating
systems, some animations will not appear
until the presentation is viewed in
Presentation Mode (Slide Show view). You
may see blank slides in the “Normal” or
“Slide Sorter” views. All animations will
appear after viewing in Presentation Mode
and playing each animation. Most
animations will require the latest version of
the Flash Player, which is available at
http://get.adobe.com/flashplayer.
DNA Fingerprinting

Used in criminal investigations:
 Detectives
and forensic scientists use DNA information
found at crime scene to understand what transpired
and who committed the crime.
 Everyone’s DNA is unique due to their variable number
tandem repeats.
Vaccines

A vaccine is a substance used to promote the
production of antibodies and provide immunity
against the pathogen being introduced.
 Substances
is either part of or completely made of a
harmless version of the pathogen.
 DNA vaccines made using one or more genes from the
pathogen.
 DNA vaccines do not have the capability of causing
disease.