Transcript Biotechnology Powerpoint

Biotechnology
Four hot topics in biotechnology:
Cloning
Stem Cells
DNA
Fingerprinting
Genetically
modified food
Biotechnology
Biotechnology: the engineering of organisms
for useful purposes.
A chimera, a mixture of a goat and a
sheep.
Animal Cloning
Megan and Morag, the world’s first cloned
mountain sheep.
Why Clone
Animals?
1. To answer questions of
basic biology
2. For herd improvement
3. For pharmaceutical
production
4. To make us happy
(e.g. pet cloning)
Prometea, the first cloned horse (in
foreground) with her identical twin and
surrogate mother Stella Cometa.
Utah State
University
(And Idaho State)
First Cloned Mule
Udder Cells
Egg Cell
1. An egg is taken from
the surrogate mother
2. A needle removes the
DNA from the egg cell.
3. An udder cell (or other
somatic cell) is taken
from the organism
being cloned.
4. The “blank” egg cell is
fused with the udder
cell.
5. Electricity stimulates
the fused cell to begin
dividing into an
embryo.
The First Cloned Pet
This is “Carbon
Copy”…the first
cloned pet.
Carbon Copy is not a
phenotypic carbon
copy of the animal
she was cloned from.
http://www.jpvpk.gov.my/html/news/archives/English/Feb02%2016B.htm
http://drsophiayin.com/blog/entry/cloning-cats-rainbow-and-ccprove-that-cloning-wont-resurrect-your-pet
Rainbow and her clone “cc”
(Science (2002) 295:1443)
The First Cloned Pet
If they are clones, why
aren’t the identical?
The genes that controls
coat color can be active or
inactive in each skin cell.
This is a random process.
Even though CC has the
gene for orange spots,
that gene has been
“turned off”
Read more about these un-identical clones here.
Is Animal Cloning Ethical?
The first cloned horse and her surrogate
mother/genetic twin.
The answer can’t be determined by
scientists alone.
Stem Cells
A stem cell is a cell that has not yet been assigned a
specific function.
During development the stem cells become specialized
White Blood Cell
Nerve Cell
Stem Cell
Skin Cell
Stem Cells
This specialization is terminal.
That means that once a cell has been specialized it
can only produce more cells like it.
White Blood Cell
White Blood Cell
Stem Cells
Where can you find stem cells?
This is a four day
old embryo called a
blastocyst. Each of
these developing
cells is a stem cell!
One of the best sources for stem cells is an
embryo of a developing fetus.
FYI: When stem cells are harvested, the embryo is
destroyed and can no longer grow into a fetus
Stem Cells
What do scientists do with stem cells?
Researchers believe that stem cells can be
used to replace damaged tissue caused by:
Cancer
Multiple Sclerosis
Parkinson’s Disease
Spinal Damage
Ethical
Questions
Are these masses
of cells a human?
If stem cells are taken
from these masses,
are you destroying
life?
More Ethical Dilemmas
At what point does an embryo become a
human?
Is it ethical to use “extra” or “left over”
embryos from In Vitro fertilization for stem
cell research?
If your grandfather developed a disease
that could possibly be cured using stem
cells, would you donate an embryo?
Stem Cells
There ARE other sources for stem cells, but they
are believed to be inferior to embryonic stem
cells:
Bone Marrow
Lipid cells
DNA Fingerprinting
What are we looking at?
The defendant stated that the
blood on his clothing was his,
was he telling the truth?
A DNA fingerprint used in a
murder case.
DNA Fingerprinting
Different individuals carry different
alleles.
Most alleles useful for DNA fingerprinting differ on the
basis of the number of repetitive DNA sequences they
contain.
DNA Fingerprinting
DNA can be cut up in pieces
of alleles. Each piece is a
different size.
A DNA fingerprint is made by
analyzing the sizes of DNA
fragment.
The DNA Fragments Are Separated on
the Basis of Size
The technique is gel electrophoresis.
The pattern of DNA bands is compared between each sample
loaded on the gel.
DNA Electrophoresis
Animation
Genetically Modified Foods
We genetically modify our food for disease
resistance, to change its taste, and to make it
grow faster and larger.
Genetically Modified Foods
What is the controversy?
A branch of government called the “Food and
Drug Administration” (FDA) is responsible for
determining if a food or drug is “safe”
For example, genetically modified salmon:
The FDA treats this as an animal drug and
not a food. This means they have a very
narrow definition of “safe” and do not
necessarily run the correct tests on the
salmon before we eat it.
http://www.sciencemag.org/content/330/6007/1052.full.pdf
Genetically Modified Foods
However, many organizations have
used what we DON’T KNOW about
GM foods to try to stop genetic
engineering of foods all together.
The “Indian Institute of Science” noted
that people have been eating GM corn
for more than a decade in several
countries, and there have been no
related health issues reported.
http://www.nature.com/nature/journal/v480/n7377/pdf/480321d.pdf
Methods for Plant Genetic Engineering are
Well-Developed and Similar to Those for
Animals
Golden Rice is Modified to Provide a Dietary
Source of Vitamin A
Golden rice (yellow) with standard rice (white).
Worldwide, 7% of children suffer vitamin A deficiency, many of
them living in regions in which rice is a staple of the diet.
However, many of these same regions have banned GM foods
Here in the U.S. more GM crops are grown each year:
Genetically Modified Crops
Genetically Modified Cotton
(contains a bacterial gene for
pest resistance)
Standard
Cotton
Biotechnology
Let’s summarize:
Four of the most talked about biotechnology
efforts are in cloning, stem cell research,
DNA fingerprinting, and genetically
modified foods.
Advances in biotechnology raise ethical
questions that scientists alone cannot
answer.