Biotechnology and Society. Learning Objectives By the end of this class you should understand: The...
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Transcript of Biotechnology and Society. Learning Objectives By the end of this class you should understand: The...
Biotechnology and Society
Learning Objectives
By the end of this class you should understand:
The advantages and risks of the major biotechnologies covered today
The use of enzyme replacement therapy
The nature of transgenic plants and animals
The processes involved in stem cell research
The applications of DNA profiling
Biotechnology
Harnessing the power of genetic information is known as biotechnology Creation of proteins from
recombinant bacterial DNA
Use of stem cells for research
DNA fingerprinting/profiling
DISCLAIMER
Today I will be covering many technologies which are still new and improving
I will attempt to survey advantages and disadvantages of each This is impossible to be precise or comprehensive
on Imagine a lecture in 1912 about the advantages
and disadvantages of powered flight!!
Biopharming
A bit of wordplay in this term Bio=life/living Pharm = drugs Also sounds like “farm”
because the drugs are farmed from living organisms
Production of human proteins using recombinant DNA
Biopharming Sample
Advantages of Biopharming
Biopharming is much safer than extracting protein from living or recently deceased organisms Pituitary extract for growth hormone was
contaminated with prions Blood extract for factor VIII was contaminated with
HIV Who knows what you're getting when you take
insulin from cows!
Disadvantages of Biopharming
No major threats posed from biopharming Except for the same
threats coming from any other lab storing large numbers of bacteria for study
As long as proper containment and sterile technique is practiced, no danger posed
Genetic Disorder Treatments
Several enzyme deficiency disorders are treatable with enzyme replacement therapy Imagine injecting PAH into
people with PKU Thus far PKU is not enzyme-
treatable but some other disorders are
Pompe disease is treatable with enzyme replacement therapy using the missing enzyme grown in hamster cells
Enzyme Replacement Therapy
Some enzyme disorders are treatable with artificially produced enzymes injected into the blood or muscles
Grown from bacteria or produced by transgenic animal for harvesting GAA enzyme (missing in
Pompe disease) originally harvested and purified from rabbit milk
Transgenic Plants
Making proteins from plants is more attractive Advantage: plants are less
cuddly and feel less pain than animals and thus likely to get fewer protesters
New breakthroughs in protein yield have made this a more promising field Many plants don't produce
much protein!
Stem Cell Research
Stem cell research is a potentially vast area of research that could carry answers to all our problems Major disadvantage:
ethics! Is it okay to fertilize
an egg and then harvest its cells for science?
Categories of Stem Cells
Embryonic stem cells have the power to turn into all 200+ types of human cells Also known as pluripotent stem cells
Adult stem cells have the power to turn into a particular group of cells Also known as multipotent stem
cells Example: Hemocytoblast produces
all blood cells
Embryonic Stem Cells Embryonic stem cells can be
harvested from a developing embryo
The harvesting of these cells produces valuable embryonic stem cell lines which can be induced to become any cell desired
The harvesting of these cells destroys the embryo which otherwise would have developed into a human being (nutrition permitting)
Many Opinions on Stem Cells
New Deal
A new way has been discovered to create pluripotent stem cells
Adult (multipotent) stem cells can be treated with genes and factors that cause their reversion to pluripotent stem cells These are induced
pluripotent stem cells (iPS cells)
Stem Cell Treatments
Many disorders are the result of a failure of a particular type of cell
– Diabetes (beta cells in pancreas), Parkinson's Disease (substantia nigra in brain), etc
These cells could theoretically be regenerated with iPS cells just the same as embryonic cells
Stem Cell Treatments
Adult stem cells have been used as treatments already!
– Skin grafts, bone marrow transplant, etc
Additional treatments may be developed using stem cells
New frontiers still being breached
– Japanese scientists just grew a liver from iPS cells this month!!
Transgenic Plants, the Sequel
Human technology has been modifying plants for millennia
– You didn't really think apples always grew that big, did you?
– Recommended book: Guns, Germs, and Steel
New technologies enable more changes faster than ever
Genetically Modified Organisms
Inserting a gene from one plant into another has huge potential advantages
– Drought resistance
– Pest and herbicide resistance
– Faster growth
– Adding new and more vitamins
Potential Risks A lot of concerns have been
raised
– Are they safe?
– Will they take over?
– Will they hybridize with weeds?
– Who profits from all this? It is a valid point that with
drought and resource strain imminent due to global warming, the payoff of GMOs should be worth the risk
Potential Risks A spirited debate is still ongoing It is vital to be rational and not simply fear the
unknown
– The unknown is pretty scary! Your book essentially brushes off all concerns
of GMOs
DNA Research
Animals can have human diseases induced for study
– We share more than 90% of our DNA with mice!
Mice can have Huntington's disease induced so it can be better studied
– Another gray area? Are mice cute enough? Do they have souls?
DNA Profiles
As mentioned yesterday, DNA can be analyzed using PCR, restriction enzymes and Southern blotting
Vital to use a variable region of human genome
– Won't get any good data from the genes for human ribosomes!
DNA Profile Technique Originally targeted variable regions called
minisatellites Today an even better variable region is used
called short tandem repeats (STRs)
– Used to create DNA profile
– DNA fingerprinting is the original name for this technique
DNA Profile Products
DNA Profile Construction
Alec Jeffreys
The first case of DNA profiling came from a serial rapist-murderer in England
In 1986 the police asked University Professor Alec Jeffreys to help
Jeffreys obtained DNA and cleared the man currently on trial
He then had police collect DNA from every man in the town
Colin Pitchfork
No man's DNA matched the DNA profile
A man bragged in a pub in the next town that someone paid him to take a DNA test
This led to the arrest of the murderer, Colin Pitchfork
– Pictured here
Keep in Mind
DNA profiling has restrictions
– Can only prove someone was in the room from hair/skin
– Can match DNA from blood, semen and saliva
– Can distinguish between relatives but not identical twins
– Takes way more time than CSI presents
Ethical Questions All these technologies present more questions
than answers! Is it legit to:
– Make a DNA profile database of everyone in the US?
– Give healthy kids growth hormone to make them better at sports?
– Give animals deadly diseases intentionally?
Enjoy the conundrums!