Biotech 101 is in Session ……
Take your• seats
Before …………
we can get to the
“Ah Ha” of new Biotech
Research Projects,
• We need to learn about:
– Basic Cell Biology
– Basic Biochemistry
– Gene Cloning
Cells: The Basic Unit of Life
Plants and Animals are multicellular
Cells are not
to scale
vacuole
nucleus
HUMAN SKIN
PLANT
BACTERIUM*
All Cells Have DNA (The “Holy Grail” of the Cell). It
resides in the nucleus or nuclear region*.
A Gene is a sequence of DNA which encodes for a Trait
(blood type, eye color, etc.)
YEAST
Review: Basic Cell Biology
Proteins
made from
DNA
message
DNA
The complete set of genes is
called the Genome
A-T-C-G….
Central Dogma of Watson & Crick:
The fundamental dogma of
molecular biology is that
genes act to create
phenotypes through a flow of
information from DNA to RNA
to proteins, to interactions
among proteins (regulatory
circuits and metabolic
pathways), and ultimately to
phenotypes (the living being).
Groups of individual
phenotypes constitute a
population
DNA
Transcription
RNA
Translation
Proteins
Circuits
Phenotypes
Populations
DNA is like videotape
Proteins: “products made from the
blueprint
the DNA”
• Essential chemicals
for cellon
structure
and activities
(reproduction, moving around, defense against
invaders, metabolism, etc.). Insulin is a protein.
• Basic unit: amino acid (~20 different ones) An
average protein has ~500 amino acids.
• The arrangement of these amino acids determine the
type of protein made
• Codons (triplet code of bases) on mRNA determines
the sequence. “Universal Code”
– AUG-UUU-... --> methionine-phenylalanine-...
1. Obtain donor DNA = (promoter (start code)+GOI*+stop code +
marker gene). *gene of interest
2. Link donor DNA to vector DNA (such as plasmid or phage) via
restriction enzymes (“scissors”) & DNA ligase (“glue”)
3. Insertion of the recombinant DNA (rDNA) into a host cell such
as bacteria, yeast, plant or animal. “Transformation”
4. Detect recombinant clone (transgenic organism) or new gene
product (protein) [marker gene helps to identify the transformed
cells]
Gene Cloning: 4 essential steps:
Example:
Insulin gene
Plasmid =
Small circular
DNA found in
bacteria and
yeast
Clone =
Identical Twin
EcoRI =
DNA-cutting
enzyme
from E.coli
A Few Applications of
Biotechnology:
• More nutritious crops with longer shelf lives.
• Higher yields per acre due to resistance to pests,
herbicides and environmental conditions such as
drought, salinity, etc.
• New & Safer vaccines and drugs, esp. for cancer
• Transgenic animals & plants which produce human
hormones, antibodies or enzymes.
• Bioremediation to clean up pollutants by altering
microbes or plants.
• Therapeutic cloning: example: grow skin cells for burn
victims
Genetic Engineering enhances the process
of Conventional Selective Breeding:
It is faster, more precise and doesn’t
require sexual compatibility
UC Davis Research:
Blumwald & Zhang’s Work
2 & 3 Have gene for transporter
Transgenic tomatoes in 5mM (A) and 200mM (B) of NaCl
Salt Tolerant Tomatoes May Hold the Key to Growing Crops
in Marginal Soils (and may even reclaim salt from the topsoil)
•
24.7 million acres of once agriculturally productive land are being lost
annually because of irrigation-induced salinity (USDA).
•
Crop production is limited by salinity on 40 % of the world's irrigated land
and on 25 % of the land in the USA.
•
Blumwald and Zhang genetically engineered tomato plants that produce
higher levels of a “sodium transport protein." Store salt in vacuole of leaves/roots
•
Plants grow and produce fruit even in irrigation water that is > 50X saltier
than normal.
Nature Biotechnology, Aug 2001
“Pharming” represents the Third
Wave of Ag Biotech
• Use of Genetically Modified Plants or Livestock as factories,
rather than food
• Plant derived medicines is not new! Examples: Taxol, digitalis,
quinine, etc.
• A plant/seed can be a high protein expression system (ex: Ventria
Biosciences in Sacto)
• Proteins can also be expressed in milk, semen or urine of cows,
pigs, rabbits, etc. Example: spider silk (Nexia)
• Significantly less costly than stainless steel tanks due to low
initial captital investment and scalability
Nature Biotechnology
Uncorking the biomanufacturing
bottleneck
Alan Dove, Aug 2002 p777-9
• “As biomanufacturing capacity becomes strained, several new methods
for producing biologics are being investigated by biotechnology
companies”
• Spokesperson from GTC Biotherapeutics (formerly Genzyme
Transgenics) in Framingham, MA estimates a 200% increase in
manufacturing capacity for Mabs alone over the next 10 years. Their
solution is milking transgenic animals (“mammary bioreactors”). PPL
Therapeutics (UK) and BioProtein (France) have similar projects. Goats,
sheep and cows are the most common mammals.
• Transgenic chicken eggs may also be feasible, but the research is still in
early stages. Companies: Origen Therapeutics (Burlingame, CA);
Avigenics (Athens, Ga); TranXenGen (Shrewsbury, MA); GeneWorks
(Ann Arbor, MI) and Vivalis (France).
Use Tobacco to make medicines
RNA
“Personalized medicine”
www.lsbc.com
Large Scale Biology (Aka Biosource) in Vacaville, Ca is
using the tobacco plant as a production system for human
vaccines, cancer therapies (ex: lymphoma) and other
pharmaceuticals. “Pharming in Plants” but no gene flow!
(Transient expression of mRNA of vaccine gene)
Increased b-Carotene in Rice Grains
Normal
Normal rice
rice
Over 120 million
children worldwide are
deficient in vitamin A.
Rice has been
engineered to
accumulate b-carotene,
which is converted to
vitamin A in the body.
Incorporation of this
trait into rice cultivars
and widespread
distribution could
prevent 1 to 2 million
deaths each year.
Introduced
enzyme
(source)
(daffodil)
(bacteria)
(daffodil)
Ye et al. (2000) Science 287: 303-305.
“Golden” rice
Edible Vaccines
Introduce antigenic proteins from disease-causing
organisms into plants. Eating the fruit or vegetable can
then induce antibodies just like a vaccination, rendering
the person immune to the disease.
The feasibility of this approach
has already been demonstrated.
Dr. Charles Arntzen of Arizona
State University. He is actively
pursuing research to allow
children to be immunized
against debilitating diseases
such as hepatitis B, for
example, by simply eating a
modified banana, potato or
tomato. Also Bill Langridge,
Loma Linda Univ. in California.
( Sci. Am., Sept. 2000)
Canada
Nexia's lead products are biomaterials and pharmaceuticals used to
treat life-threatening disease. Nexia produces these recombinant
proteins in the milk of transgenic BELE® goats from which they
are extracted. Nexia will further process the milk to purify
recombinant products. BioSteel™ filaments are environmentally
friendly and will be used in applications where strength and
flexibility are required, such as medical devices or body armor.
Who Assures Safety of Biotech ?
Agency
Products Regulated
• U.S. Department of plant pests, plants, veterinary Agriculture (USDA)
biologics, animals, fish
(Safe to Plant)
• Environmental
microbial/plant pesticides, Protection
new uses of existing
Agency (EPA)
pesticides, novel
microorganisms
(Safe for the Environment)
• Food and Drug
food, feed, food additives, Administration
veterinary drugs, human
(FDA)
drugs
and medical devices
(Safe to Eat)
Web Sites for Information:
•
To see a weekly summary of world developments in agri-biotech , produced by
the Global Knowledge Center on Crop Biotechnology, International Service for
the Acquisition of Agri-biotech Applications (ISAAA), and CAB International.
(http://www.isaaa.org)
•
Essential Biosafety CD: http://www.essentialbiosafety.info (free). This CDROM offers comprehensive information about the safety of genetically modified
crops. Second edition will be released in Nov, 2002.
•
Food Biotechnology: A Communication Guide to Improving Understanding is
available! This Guide aims to raise awareness of this communications issue, and
provides lots of practical advice and resources to overcome this problem.. Get
your free CD by e-mailing a request to knowledge.center@isaaa.org.
We have been here before!
We have recently advanced our knowledge of
genetics to the point where we can manipulate
life in a way never intended by nature.
We must proceed with the utmost caution in the
application of this new found knowledge.
LUTHER BURBANK, 1906