4. • Genetic engineering involves changing
the genetic material in an organism to
alter its traits or products
• A recombinant DNA molecule contains
DNA fragments spliced together from 2 or
more organisms
5. Stages of cloning experiment
Elements:
Vectors
Restriction enzymes
Mechanism in joining the fragments
Selection or detection of successful cloning
Gene library
6. 1. Joining
DNA segment
Vector 2. Providing
milieu that
allows
propagation
Clones
7. 1. Remove bacterial DNA (plasmid).
2. Cut the Bacterial DNA with
“restriction enzymes”.
3. Cut the DNA from another
organism with “restriction
enzymes”.
4. Combine the cut pieces of DNA
together with another enzyme and
insert them into bacteria.
5. Reproduce the recombinant
bacteria.
6. The foreign genes will be expressed
in the bacteria.
8. 1. It must be able to replicate
2. There must be some way to introduce
vector DNA into the cell
3. There must be some way of detecting its
presence, preferably by plating techniques
Most common vectors are:
Plasmid, phage λ and viruses
9. Discovered in an experiment where
bacteriophage lost its plaque formation in
E.coli
Enzymes that recognize a specific base
sequence in a DNA molecule
It makes two cuts, one in each strand,
generating 3’-OH and 5’-P termini
Types of termini produced:
Flush or blunt end
Cohesive or sticky end
10.
11.
12. The number of cuts made in the DNA from
specific organism is limited
A particular restriction enzyme generates a
unique family fragments from a DNA
molecule
14. Restriction maps show the relative location of a selection of restriction sites along
linear or circular DNA.
EcoRI
HindIII
PstII BamHI
HindIII BamHI PstII
25. collection of all of the vector molecules, each
carrying a piece of the chromosomal DNA of
the organism
Hinweis der Redaktion
This events could be so complex when using natural and random mutagens and then selection. That is why scientists develop technology that can modify organism in directed and predetermined way