genetically modified organisms
TRANSCRIPT
What are GM’s?
Organism one that has been altered through
recombinant DNA technology
Involves either the combining of DNA from
different genomes or the insertion of foreign DNA
into a genome
The most common genetically modified (GM)
organisms are crop plants
Microbes are the first organisms to be genetically
modified
Other terms that mean the
same thing:
Genetically engineered
Transgenic
Recombinant DNA (rDNA) technology
What is not a GMO?
Does not include
Mutants.
Fusion of animal cells unless the product can form an
animal.
Plants formed x protoplast fusion.
Plants formed by embryo rescue or invitro fertilisation or zygote implantation.
Organisms formed by natural DNA transfer.
How does this differ from
Mendel and his peas?GM vs. Selective breading
Selective breading
Slow
Imprecise
Modification of genes that naturally occur in the organism
Occur between plant/animal of same species(dog dog)
GM
Very fast
Precise
Can introduce genes into an organism that would not occur naturally
It can occur between different types of species
(Human bacteria)
How transgenic organisms
work…Three Main Methods…
DNA Microinjection
A foreign gene is directly injected into a fertilized egg that is put into a female animal that acts as a surrogate mother for the egg.
Retrovirus-Mediated Gene Transfer
A retrovirus is a virus that attaches to an organism’s DNA and changes it to include a new characteristic. Scientists expose ordinary cells to a retrovirus when they are trying to create transgenic animals.
Embryonic Stem Cell-Mediated Gene Transfer
Stem cells are blank cells that can turn into any type of cell. Scientists modify these cells, and then add them to an embryo, which is a fertilized egg that develops and grows until it hatches or is born.
DNA MICROINJECTION
Most commonly used
method
Only 5% or less of the
treated eggs become
transgenic progeny
Need to check mouse
pups for DNA , RNA and
protein ( by some
specific assay method)
Expression will vary in
transgenic offspring:
due to position effect
and copy number
Figure 1.1
Figure 1.2
Less than 5% of the microinjected fertilized eggs become
transgenic progeny
Figure 21.1
Retroviral vectors
can be used to
create transgenic
animals
RETROVIRUS-MEDIATED GENE
TRANSFER
Figure 1.4
Genetically
engineered
embryonic stem (ES)
cells can be used to
create transgenic
animals
This method allow for
gene targeting via
homologous
recombination.
EMBRYONIC STEM CELL-
MEDIATED GENE TRANSFER
GENETICALLY ENGINEER OF THE ES CELLS
Figure 1.5a
GENETICALLY ENGINEER OF THE ES CELLS
Figure 1.6b
THE TWO MOST COMMON TYPES OF GMO’S
I. FOODS
Crops are modified to develop resistance to
herbicides and increase their nutrient
content, for example corn and soybeans .
Fruits are modified to make them ripen later.
This help them available fresh in marketplace
during a longer time or for fruits that ripen
after being picked, make it easier to
transport them.
THE TWO MOST COMMON TYPES OF
GMO’SII. MEDICINES
These can be produced cheaper and easier
some are: insulin, thyroid hormones and the
Hepatitis B vaccine
GM Bacteria’s have been particularly important in
producing large amounts of pure human proteins
for use in medicine like clotting factors for
hemophilia and human growth hormones to treat
dwarfism
OTHER TYPES OF GMO’S ARE
III. MAMMALS
Research human diseases
(To develop animal models for many diseases.)
Produce industrial or consumer products
(pharmaceutical products or tissue implantation)
Enrich the animals’ interactions with humans
(Hypo-allergic pets)
Enhance production or food quality traits
(faster growth fish, pigs that digest food more
efficiently)
Improve animal health(disease resistance)
OTHER TYPES OF GMO’S AREIV. INSECTS
The effects of genetic changes on development
(malaria resistant mosquitoes)
V. AQUATIC LIFE
Evolution of immunity and developmental processes,
rapid growth
( MADAKA -fish to detect pollutions in waterways)
TRANSGENIC MONKEY
Its so similar to human hence it used in
clinical trail used for studying :
º HIV
º Huntington’s disease
DISADVANTAGES
Expensive
Difficult
Breeding problem
GOAT THAT PRODUCE SPIDER SILK
Two key genes that allow a spider to weave their silk inserted into their genetic code.
That produce milk that contain spider silk proteins
Proteins are then harvested through the goat's milk
Goats are separated into two groups, each contains one of the two proteins
Proteins must be extracted and combined
GOAT THAT PRODUCE SPIDER SILK
Stronger than steel and
more flexible
Used to replace
damaged tendons and
ligaments , suture
damaged eyes, or even
nerves
Make stronger and safer
parachutes for soldiers ,
bulletproof vests
SILK FROM MILK
Goats are milked
Milk is frozen and the cream is separated
Thawed milk is pushed into a micro filter that
blocks the larger fat molecules and lets the
smaller proteins through
A smaller filter then further isolates the silk
proteins
When dried looks like a white powder
CURRENT RESEARCH
Mosquito-borne diseases remain one of the greatest global threats to human health
With recombinant and novel combinations of DNA passing into the environment
Effects of gm plants on soil processes such as decomposition
Lactococcus lactis secreting interleukin 10 provides a therapeutic approach for inflammatory bowel disease
CONCLUSION
Transgenic animals are now-a-days used for
screening of many drugs
Using of transgenic animals reduce number of
experimental animals during testing
We will need them in the future