2. *INTRODUCTION
It is a molecular biotechnology technique in which DNA fragments
from different sources are joined together to create a newly
modified DNA fragment of desired interest .
Also K/A recombinant DNA(rDNA) or a chimera.
6. The hosts are the living systems or cells in which the carrier of
recombinant DNA molecule or vector can be propagated.
7.
8. Phages (bacterial viruses)
Viruses infecting bacterial
species and multiplying within
it.
Larger fragments of DNA can be
cloned in cosmids,which combine the
best features of plasmids and phages.
Bacterial plasmids are
small, circular, duplex
DNA molecules that exist
in bact.cells and Naturally
confer antibiotic
resistance to the host cell.
These vectors are often
derivatives of plasmid pBR322
and contain the
necessary transcription and
translation start signals.
11. The various general steps involved in the preparation of Recombinant DNA can be briefly
Summarized As:
(1) Selection of DNA of interest
(foreign or target or passenger DNA)
(2) A cloning vector (to carry inserted pieces of target DNA)
(3) DNA ligases
(which joins pieces of two different DNA molecules together)
(4) Restriction endonucleases enzymes mostly RE-TYPE2 is used.
(which makes internal cuts at specifics sites on DNA )
(5) Host (to replicate the vector containing foreign
DNA: Prokaryotic / Eukaryotic cell).
(6) Screening test for recombinants produced by insertion of
DNA.(PCR,DNA Sequencing,NAH,BLUE WHITE SCREENING).
STEPS IN rDNA FORMATION
25. OTHERS
2. Development of Transgenic Plants:
EG: BT-cotton, resistant to bollworms is a glaring example.
3. Production of Transgenic AnimalS
Cow, sheep, goat – therapeutic; human proteins in their milk. Fish like
common carp, cat fish, salmon and gold fish contain human growth
hormone (hGH).
4. Industrial Applications:
In industries, recombinant DNA technique will help in the production of
chemical compounds of commercial importance, improvement of
existing fermentation processes and production of proteins from
wastes.
26. RECENT ADVANCES:
Second Generation Therapeutic Proteins (Muteins):
• By employing site-directed mutagenesis, the amino acid sequence
of a recombinant protein can be suitably modified as desired, by a
technique referred to as protein engineering. The mutated
proteins are collectively referred to as muteins.
• Protein engineering is a rational approach to modify a protein with
regard to its stability, solubility, specificity, substrate affinity,
pharmacokinetics etc.
• The muteins obtained by protein engineering technique are
considered as Second generation of therapeutic proteins.
• Selected examples of such proteins (e.g. insulin lispro, Alteplase).
27. REFERENCES
• 1. R.MURRAY,D.BENDER HARPER’S BIOCHEMISTRY,28e,p388-
404.
• 2.U.SATYANARAYANA,U.CHAKRAPANI BOOK OF
BIOCHEMISTRY,3rde.
• 3.GG 13e.
