11/9/2015
1
Biology 102Biology 102
Lecture 13: BiotechnologyLecture 13: Biotechnology
Part 1Part 1
BiotechnologyBiotechnology
•• The use or alteration of organisms, cells, or The use or alteration of organisms, cells, or biomoleculesbiomolecules to produce food, drugs, or other to produce food, drugs, or other goodsgoods
•• Has huge potential for benefitHas huge potential for benefit
•• Has some risks and ethical questions as wellHas some risks and ethical questions as well
BiotechnologyBiotechnology
•• People seem to think that biotechnology is newPeople seem to think that biotechnology is new
•• Truthfully, we’ve been doing this foreverTruthfully, we’ve been doing this forever
BiotechnologyBiotechnology
•• But now our technology changes rapidly and is But now our technology changes rapidly and is capable of morecapable of more
TopicsTopics
•• Stem cells and cloningStem cells and cloning
•• Genetic engineeringGenetic engineering
•• Forensic technologyForensic technology
•• Medical diagnosis and treatmentMedical diagnosis and treatment
•• ResearchResearch
What are Stem Cells?
Stem cells are nonStem cells are non--differentiated cellsdifferentiated cells(no specific function)(no specific function)
Able to divide and multiply indefinitelyAble to divide and multiply indefinitely
Two types:Two types:
1.1.Embryonic Stem CellsEmbryonic Stem Cells
2.2.Adult Stem CellsAdult Stem Cells
11/9/2015
2
What are Stem Cells?
•• Remember: all cells in the body contain the Remember: all cells in the body contain the same chromosomessame chromosomes
•• This is because all cells in our body come This is because all cells in our body come from the same fertilized eggfrom the same fertilized egg
Human DevelopmentHuman Development
Human DevelopmentHuman Development
Kidney cells
Stomach cells
Nerve cells
Muscle cells
Blood cellsBone cells
The Human BodyThe Human Body
• Totipotent cell – any cell type, including extra-embryonic
• Pluripotent cell – any cell type, not including extra-embryonic
• Multipotent cell – multiple cell types
• Unipotent cell – one cell type
ESC are cells isolated from 5-6 day old embryosthat can become any cell in the human body
Cell Potential
ESC are pluripotent cells
Embryonic Stem Cells (ESC)Embryonic Stem Cells (ESC) Embryonic Stem Cells
ESC are derived from the inner cell mass of a 5-6 day old embryo – called a blastocyst
2 cells 4 cells 8 cells 16 cells 70-100 cells
Inner cell mass
11/9/2015
3
Cultured stem cells
Multipotent cells found in small numbers within specific tissues
• Bone• Blood• Muscle• Liver• Skin• Nerves
Examples:
Adult Stem Cells (ASC)Adult Stem Cells (ASC)
Why would the adult body need stem cells?
Problems with Adult stem cells
� Specific for certain tissue(s)
� Small number of cells
� Hard to culture
� Lacking research
• Adult stem cells have been used for years (bone marrow transplants)
• In animal models, used to treat diseases
• More advanced techniques show promise
• No ethical concerns
Adult Stem Cells (ASC)Adult Stem Cells (ASC)
Special type of multipotent stem cells
Umbilical Cord Stem CellsUmbilical Cord Stem Cells
Can be used for transplants later in life
Some parents choose to bank cord blood forthis purpose = $$$$$$$
Pluripotent Multipotent
Liver Nerve Blood
Embryonic SC Adult SC
Why study Stem CellsMany Potential Uses:
1.Study Human Development
� Cancer & Genetic Disorders
2.Test New Drugs
� How specific tissues react to new drugs
3.Cell-Based Therapies:
� Several types
11/9/2015
4
Cell-Based Therapies
• Repair damaged tissue
� Bone marrow transplant in Leukemia patients
Cell-Based Therapies• Repair damaged tissue
� Bone marrow transplant
� Spinal cord injuries
− Severed rat spinal cord fixed
The Journal of Neuroscience. March 29, 2006
Cell-Based Therapies• Repair damaged tissue
� Bone marrow transplant
� Spinal cord injuries
� Type 1 diabetes
� Degenerative diseases
Cell-Based Therapies• Repair damaged tissue
� Bone marrow transplant
� Spinal cord injuries
� Type 1 diabetes
� Neurodegenerative diseases
• Replace damaged tissues or organs
� Growing organs for transplantation
� Heart, kidney, lungs, liver
Solves the problem of tissue rejection
Types of Cloning• Molecular cloning (DNA cloning)
– Manipulating a small piece of DNA, typically using bacteria
as host
• Reproductive cloning
– Technique used to generate an animal with exact genetic
makeup (DNA) as another animal
• Therapeutic cloning
– Creating stem cell lines with same DNA as a patient, used
for treating diseases and disorders
11/9/2015
5
Cloned Stem Cells
• Immune system will recognize & destroy cells with different DNA
• Therefore, stem cells need to contain same DNA as patient
• Cloned Stem Cells -
• Somatic Cell Nuclear Transfer
“Therapeutic Cloning”
� Somatic cells = all body cells except gametes
� Nucleus = region of cell containing DNA
� Transfer = remove and replace
Normal Embryo Formation
23 chromosomes23 chromosomes 23 chromosomes23 chromosomes
46 chromosomes
• Each sex cell contains 23 chromosomes
• The two sets of chromosomes come together to form a unique individual
Nucleus removed & saved
Nucleus donor
Somatic Cell Nuclear Transfer
“Reproductive Cloning”
Surrogate Mother
Clone produced
Nucleus discarded
Egg donor
Egg
Insert saved
nucleus into egg
Stimulate egg to divide
Hello, Dolly!
Nucleus removed & saved
Nucleus donor
Somatic Cell Nuclear Transfer
“Reproductive Cloning”
“Therapeutic Cloning”
Surrogate Mother
Clone produced
Nucleus discarded
Egg donor
EggIsolate ESC, use for Cell-Based
Therapies
Insert saved
nucleus into egg
Stimulate egg to divide
Therapeutic Cloning
11/9/2015
6
Problems & Controversies
• Tissue rejection
• Should be overcome by cloned stem cells
• Viruses
• Standard culture media contains mice feeder cells
• Cancer
• Stems cells may pose a cancer threat
Main Problems w/ Stem Cell Research
Controversies
“Making Human Clones”
If SCNT is developed for Cell-Based Therapies,then rouge scientists could abuse the technology
ControversiesIs Embryonic Stem Cell Research Murder?
Stage at which ES cells are removed and embryo destroyed
ESC procedures do not use aborted fetuses(Fetal stem cell technology is different)
Many frozen embryos are have been or will be discarded
Is it alive?
Current Policy
� No law ever banned stem cell research in the US, only placed restrictions on funding and use
� On August 9, 2001, President George Bush announced NIH will fund embryonic stem cell research for the first time.
� In 2009, President Barack Obama allowed new hESC lines to be created with federal funds
� Embryos must have been created for reproductive purposes, but discarded and donated with consent
� It is currently not legal in the US to create human embryos purely for research purposes
New Research
What does it mean?
• First cloned embryo in a primate
Significance:
• Technology likely to transfer to humans
• Cloned hESC ���� cell-based therapies to treat disease
• Cloned hESC ���� human clones??
11/9/2015
7
New Research
What does it mean?
• Destroying embryos not required for stem cell lines
Significance:
• Still uses fertilized egg, so not a genetic match to patient
New Research
What does it mean?
• Reprogramming body cells into pluripotent stem cells
Significance:
• Stem cell lines produced that are an exact genetic match to the patient ���� cell-based therapies
• No embryo involved
• Everyone could have own stem cell line
• Technology far from fruition
Conclusions• Embryonic SC = pluripotent ���� any body cell
• Adult SC = multipotent ���� several cell types
• Cell-based therapies could treat many diseases
� Repair or replace damaged tissues or organs
• SCNT not yet available in humans
� Cloned stem cells
• Reprogramming body cells, while a new technology, is very promising
� Could alleviate many controversies
Types of Cloning
• Molecular cloning (DNA cloning)
– Manipulating a small piece of DNA, typically using bacteria as
host
• Therapeutic cloning
– Creating stem cell lines with same DNA as a patient, used for
treating diseases and disorders
• Reproductive cloning
– Technique used to generate an animal with exact genetic
makeup (DNA) as another animal
Genetic Engineering
Recombinant DNA - combining DNA molecules not
found together in nature; via cloning
Making Human InsulinMaking Human InsulinGenetically Modified Organism (GMO):
– an organism that contains foreign DNA
– w/ altered characteristics
– does not occur
naturally
– obtained via cloning
technology
42
11/9/2015
8
How are GMOs made?
• Cloning
– Not reproductive cloning
• Duplicate animal
– Not therapeutic cloning
• Stem cell research
George and CharlieGeorge and Charlie
DollyDolly
43
DNA Cloning –
– Molecular cloning
– Inserting foreign DNA
from one organism into
another
what is it?
44
Where are GM foods?
The Marketplace
– 80% of processed food
contains GMO
In the US:
– Corn ~88% is GM
– Soybean ~93% is GM
– Cotton ~94% is GM
– Canola ~90% is GM
45
47
What types of crops?
– canola
– rice
– corn
– soybean
– cotton
– squash
– papaya
– sugar beet
– potato
– chicory
– tomato
– apple
– mango
– banana
– pineapple
– barley
– sweet potato
– coconut
– flax
– zucchini
Past, present and future
48
11/9/2015
9
What’s being put in the plants?
• Insect resistance (corn, cotton, potato, tomato)
• Bt (Bacillus thuringiensis)
• Benefits
– Plants produce their own pesticide
– Reduction in crop loss due to caterpillars
– Non-toxic to humans
• Concerns
– Short half-life on the surface of plants, but not when the
plant keeps making it
– Non-target species are killed, such as butterflies and bees
• Even from exposure to just the pollen
– Emergence of secondary pests
49
What’s being put in the plants?
• Herbicide resistance (corn, soybean, cotton, canola,
sugarbeets, rice, flax)
• Glyphosate (= RoundUp)
• Benefits
– Herbicide can be applied at any time in plant’s life cycle
– Reduces production cost, crop loss
• Concerns
– Environmental impact of increased herbicide use
– Antimicrobial – unknown impact on human
microbiome
50
What’s being put in the plants?
• Virus resistance (squash, papaya, potato, sweet potato)
• Delayed fruit ripening (tomato)
• Altered oil content (canola, soybeans, rapeseed)
• Pollen control (corn, chicory)
51
Potential Benefits of GMOs• Increased productivity
• Reduced cost (?)
• Better resistance
• Better nutritional content (?)
• Disease treatment (human)
• New materials and energy sources
52
General GMO Concerns
• Human health
– Long-term health consequences unknown, because the
studies are impossible or unethical
– Possible secondary effects
• Example: rBST
– The USDA says they’re safe, they’re probably (mostly) right
– But they’ve been wrong before…
53
General GMO Concerns
• Human health
– Unexpected allergens
– Example: GMO soybeans with Brazil Nut proteins
+
54
11/9/2015
10
General GMO Concerns
• Environmental
– GMO plants may cross-pollinate with wild varieties
• “Super weeds”
– Less judicious herbicide/pesticide use
– Impact on non-target species
– Emergence of secondary pests
55
General GMO Concerns
• Political
56
General GMO Concerns
• Political
57
General GMO Concerns
• Political
58
Dairy and Meat Products
• 70% of cheese made from genetically engineered enzyme
• Milk from cows treated w/ growth hormone (increase
production)
• Livestock eats GM feed
• Currently no GM meat is available
– Awaiting FDA decision on GMO salmon since
December 2014
59
Genetic engineered plants produce pharmaceutical drugs or chemicals
Biopharming
What is it?
What’s in the future?
– Edible vaccines
– Plantibodies
– Plant made plastics
– Fuel compounds (alcohols)
– Therapeutic proteins
60