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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
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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
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)
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
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?
