GENETIC ENGINEERING AND RECOMBINANT DNA TECHNOLOGY

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11 Δεκ 2012 (πριν από 4 χρόνια και 4 μήνες)

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GENETIC ENGINEERING AND RECOMBINANT DNA TECHNOLOGY



I.
GENETIC ENGINEERING
-
the transfer of genes from one chromosome to another.


A. This has become a much studied area in the field of genetics. It is also very controversial.


B. Genetic engineeri
ng can be conducted in a variety of ways.


II.
RESTRICTION ENZYMES
-
special enzymes that can be used to isolate and remove a specific DNA


fragments and genes. These have become very useful in genetic engineering studies.

III.
RECOMBINANT DNA TECHNOLO
GY
-
involves the use of DNA from two or more different


sources.


A.
Plasmids
-
small circular fragments of DNA found in some bacteria.



1. These contain only a few genes. They often contain genes that provide the bacteria




with the ability to d
evelop resistance. These also contain genes that help the bacteria




breakdown certain materials.


B.
Example of Recombinant DNA Technology using Plasmids



1. See page 250
















2. There are
two types of enzymes used in this procedure
:




a.

Restriction enzymes




b.
DNA Ligase
-
what does this enzyme do?



3. Once the bacteria are engineered to produce human insulin, they are cloned.
Gene





cloning

refers to the production of identical copies of a specific gene.



4. Plasmids are also bei
ng examined to see if they can produce the following:




a.
Interferons









b.
Clot factors






c.
Erythropoietin



IV.
THE POLYMERASE CHAIN REACTION (PCR
)
-
process in which copies of DNA can be produced


very rapidly.


A. This process can make
copies of specific segements of DNA.


B. The enzyme
DNA polymerase

is used in this process.


C. Now, there are actually machines that are used to carry out polymerase chain reactions.


D. As mentioned earlier, PCR creates specific segments of DNA. These s
egments can be



analyzed using a procedure known as
DNA Fingerprinting
.



1. By using a process known as
Gel Electrophoresis
, DNA segments can be separated




according to their charge and size. This results in a series of distinctive bands. This




procedure is currently being used in crime investigations.

V.
EXAMPLES OF GENETIC ENGINEERING IN AGRICULTURE










VI. Genetic engineers are currently looking at viruses to treat certain illnesses.


A. The researchers are trying to develop, throug
h genetic engineering, viruses that are programmed



to attack and kill specific pathogenic cells in the body.

VII.
STEM CELL RESEARCH


A. Animals, including humans, contain stem cells.



1. These are cells that can develop into the various tissues t
hat make up a living organism.



2. Development of these cells begin when stem cells are subjected to certain chemicals




such as hormones.


B. All living animals contain stem cells, however, they are most abundant and easy to find in




C. Researchers

are trying to determine what makes stem cells develop into certain tissues. If this



can be discovered, then stem cells could possibly used to treat:






VIII.
GENE THERAPY
-
involves the insertion of genetic material into human cells for the treatme
nt of


a disorder.