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!