2. Genetic engineering is the process of taking
genes and segments of DNA from one
species and putting them into another
species, thus breaking the species barrier
and artificially modifying the DNA of
various species.
3. O These changes in DNA result in an
alteration of reproductive and hereditary
processes of the organisms since the
process is irreversible and the organism's
offspring will also possess this unique
DNA (Levine).
4. O Genetic engineering can be done on any
living organism because all living
organisms contain DNA within each cell
nucleus.
O Genetic engineering involves the
manipulation of DNA and the transfer of
gene components in order to encourage
replication of desired traits.
6. 1. Determination of the gene
O it is important first to understand the
structure of deoxyribonucleic acid, or
DNA. DNA stores the information that
determines an organism's hereditary or
genetic properties. Genetic engineering is
based on this genetic information.
7. recombinant-DNA formation,
or gene splicing.
• Genetic manipulation
• This procedure whereby segments of genetic
material from one organism are transferred to
another.
• The basis of the technique lies in the use of
restriction enzymes that split DNA strands
wherever certain desired sequences of
nucleotides, or specific genes, occur.
• This desired segment of DNA is referred to as
donor DNA. The process of gene splicing results in
a series of fragments of DNA, each of which
express the same desired gene that can then
combine with plasmids (Rubenstein).
8. 3. Insertion of plasmid
• Plasmids are small, circular molecules of DNA that
are found in many bacteria.
• The bacteria act as vectors in the process of
genetic engineering. The desired gene cannot be
directly inserted into the recipient organism, or
host, therefore there must be an organism that can
carry the donor DNA into the host.
• Plasmid DNA is isolated from bacteria and its
circular structure is broken by restriction enzymes
(Dworkin). The desired donor DNA is then inserted
in the plasmid, and the circle is resealed by
ligases, which are enzymes that repair breaks in
DNA strands.
9. 4. Cell replication (division)
• This reconstructed plasmid, which
contains an extra gene, can be replaced
in the bacteria, where it is cloned, or
duplicated, in large numbers.
• The combined vector and donor DNA
fragment constitute the recombinant-DNA
molecule. Once inside a host cell, this
molecule is replicated along with the
host's DNA during cell division.
• These divisions produce a clone of
identical cells, each having a copy of the
recombinant-DNA molecule and thus
permanently changing the genetic
makeup of the host organism
15. Somatic Therapy
• Somatic therapy is a type of genetic therapy that only
affects the individual.
• Changes are not passed on to any subsequent
generations or off spring.
16. Germ line Therapy
• Germ line therapy is a type of genetic therapy that not
only affects the individual but also the off spring.
• Changes are passed on to subsequent generations.
17. Splicing
• Splicing is a method where genes from one
organism are “spliced” into the DNA of another
organism. This is the most common method of
genetic engineering.