LESSON 1: RECOMBINANT DNA
DNA LIGASES
DNA join together fragments of newly
● Deoxyribonucleic Acid synthesized DNA to form a seamless
● Double stranded strand.
● Blueprint of life
● Contains the instructions needed for Steps in Creating Recombinant DNA:
an organism to grow, develop, 1. Isolate DNA from two sources (gene
survive, and reproduce of interest and plasmid).
2. Cut both DNAs by the "restriction
GENETIC ENGINEERING enzyme".
Artificial manipulation, modification, and 3. Combine the DNAs and seal using
recombination of DNA or other nucleic acid "DNA ligase".
molecules in order to modify an organism or 4. Transfer the recombinant DNA
population of organisms. plasmid into the bacterial cell
5. Isolation and insertion to other
Classical Breeding organisms to confer the desired trait.
The practice of mating or breeding selected
organisms with desirable traits. Transgenic is an organism or
microorganism that has genetic material
Steps in Classical Breeding: from some other organism.
1. Determine which traits are significant
enough to be chosen. Donor Cell contains the ‘genetic interest’.
2. Select parents that exemplify these
traits. The plasmid is the common vector in this
3. Choose the best offspring from situation. A vector can be thought of as the
parents to produce the next vehicle for getting the recombinant DNA into
generation. the organism.
4. Repeat the process.
LESSON 2: RECOMBINANT DNA: The
Recombinant DNA Technology Practical Applications of DNA-based
Modification in genetic engineering involve Biotechnology
the following:
1. Introduction of new traits into an Applications of Genetic Engineering or
organism DNA-Based Biotechnology
2. Enhancement of a present trait by
increasing the expression of the A. Diagnosis and Treatment of Diseases
desired gene. ● Identification of genes
3. Enhancement of a present trait by lead to ways of diagnosing, treating, and
disrupting the inhibition of the even preventing genetic disorders /
desired gene’s expression. diseases, and understanding of
"non-genetic" diseases well.
Role of Enzymes in Producing rDNA Example: PCR (Polymerase Chain
Reaction)
RESTRICTION ENZYME ● Gene Therapy
is a DNA-cutting enzyme that recognizes a The introduction of genes into an afflicted
specific target sequence (restriction site) individual for therapeutic purposes.
and cuts DNA into two pieces at or near that Example: gene therapy using retroviral
site. vector
Example: PCR (Polymerase Chain Reaction)
Polymerase chain reaction (abbreviated
PCR) is a laboratory technique for rapidly
producing (amplifying) millions to billions of
copies of a specific segment of DNA, which
can then be studied in greater detail.
Example: many bacteria can extract heavy
B. Pharmaceutical Products metals, such as copper, lead, and nickel,
● Protein Production in Cell from their environments and incorporate the
Cultures metals into compounds such as copper
DNA cloning and gene expression systems sulfate or lead sulfate, which are readily
for producing large quantities of a chosen recoverable.
protein that is present naturally in only
minute amounts. E. Agricultural Applications
Example: human insulin and human growth ● crop plants with genes for desirable
hormone (HGH), and tissue plasminogen traits, such as delayed ripening and
activator (TPA). resistance to spoilage, disease, and
● Protein Production by "Pharm" drought, and provided modifications
Animals that added value to food crops,
A gene (or DNA) can be introduced from an giving them a longer shelf life or
animal into the genome of another individual improved flavor or nutritional value.
(often of a different species), which is then ● Crops resistant to a herbicide can
called a transgenic animal (can act as grow while weeds are destroyed,
pharmaceutical "factories.") and genetically engineered crops
Example: anti-thrombin, which prevents that can resist destructive insects
blood clots, can be inserted into the genome reduce the need for chemical
of a goat. insecticides.
Other Applications of Genetic Genetically modified Plants
Engineering
BT corn
● Human Insulin - Bacillus thuringiensis
- resistant to corn-borer disease.
C. Forensic Evidence and Genetic
Profiles BT eggplant
● Forensic Evidence - Bacillus thuringiensis
Forensic laboratories can determine the - resistant to eggplant fruit and shoot
blood type or tissue type by using borer (ESFB)
antibodies to detect specific cell-surface
proteins from body fluids or small piece of Beta-Carotene
tissue left at the scene of the crime. - (Pre-cursor vitamin A)
● Genetic Profiles or "DNA
Fingerprints" ETHICAL ISSUES/CONCERNS
Genetic markers that vary in the population ● Nearly 50 countries around the
can be analyzed for a given person to world, including Australia, Japan and
determine that individual's unique set of all of the countries in the European
genetic markers, or genetic profile. Use of Union, have enacted significant
genetic profiles can provide definitive restrictions or full bans on the
evidence. It is also useful in parenthood production and sale of genetically
disputes and in identifying the remains of modified organism food products,
crime victims. and 64 countries have GMO labeling
requirements.
D. Environmental Cleanup
● Genetically engineered Some issues to consider when deciding
microorganisms may become whether to create and/or use GMOs
important in both mining (especially include:
as ore reserves are depleted) and 1. Safety- Are GMO foods safe for
cleaning up highly toxic mining human consumption? Is GMO feed
wastes. healthy for animals?
● These microorganisms could be 2. Environmental Impact- Biodiversity
used in wastewater treatment plants loss
or by manufacturers before the 3. Humans- Should humans be
compounds are ever released into genetically engineered? Doing so
the environment. could have medical applications that
reduce or prevent genetic disorders
such as Down's syndrome. However,
the bigger question is where should
engineering humans stop? Should
parents be allowed to decide their
children's eye colors, heights or
even genders before birth?
- Can make deadly pathogens
(biological weapons)
