Transcript Chapter 14 Power Point Slides

Michael Cummings
Chapter 14
Biotechnology and Society
David Reisman • University of South Carolina
Biotechnology
 Biotechnology
• The use of recombinant DNA technology to produce
commercial goods and services
• Chp13 discussed how DNA from different organisms
could be combined to create specific DNA molecules
with the ability to grow in various types of cells.
(1970’s)
• Now, recombinant DNA technology is making a direct
impact on our everyday lives.
• This has generated unresolved ethical issues.
Biotechnology
 …in this chapter
1. Pharmaceutical products made in transgenic plants
and animals
2. Use of stem cells to treat disease
3. GMOs
4. Use of animals that model human diseases
5. Use of DNA in forensics and other fields
14.1 Biopharming: Making Human Proteins
in bacteria, cells, and animals
 Before biotechnology insulin, growth hormone, blood-clotting
factors were isolated from animals and/or human blood
donations—often contaminated with HIV or hepatitis virus ,
some patients had a negative reaction to the animal protein.
 As of 1982 insulin production utilized bacteria that were
engineered to make human insulin—pure and reliable.
 Blood-clotting factors made in hamster cells using
recombinant DNA technology began in 1990s
Some Products Made by
Recombinant DNA Technology
Table 14-1, p. 314
Human Proteins
Can Be Made in Animals
 Transgenic
• The transfer of genes between species
 Transgenic organism
• An organism that has received a gene from another
species by means of recombinant DNA technology
Human proteins made in animals
Use recombinant DNA technology to express a human
protein in the mammary glands of a cow, sheep, goat,
(rabbits and hamsters used in early experiments)
then patients drink the milk from these transgenic
animals
•
•
•
•
For enzyme-replacement therapy as in Pompe disease
Blood-clotting factors for hemophiliacs
Collagen
Antibodies (vaccines)
Large Scale Synthesis of Human GAA-Pompe disease
Rather than using an entire animal,
only animal cells are used to make a
recombinant protein for medical use.
Fig. 14-3, p. 315
The Use of Transgenic Plants
 Gene transfer into crop plants can result in the
production of human proteins
• Lower costs
• Easier to grow
• Using corn to make human collagen:
http://www.inpharm.com/news/161608/us-teammake-human-biocollagen-plants
14.2 Using Stem Cells to Treat Disease
 Embryonic stem
cells: from the inner
cell mass of early
embryos. These
cells are pluripotent
and can form many
different cell types.
Inner cell mass
Fig. 14-4a, p. 316
Additional Classes of Stem Cells
 Adult Stem cells: recovered from bone marrow or
other organs. Can develop into a limited number of
mature cells, thus are considered multipotent.
 Induced plutipotent stem cells (iPS): adult cells
reprogrammed by transferring several master
control genes into the nucleus. They behave similar
to embryonic stem cells.
Generation of Induced Puripotent Stem
Cells
Stem cell Based Therapies may Treat many
Diseases
 Can be used to replace defective cells
Table 14-2, p. 317
Stem cell Based Therapy for the Treatment
of Burns
Fig. 14-8, p. 318
iPS cells from patients with specific
disorders
 Producing induced pluripotent stem cells from
individuals with genetic diseases provides a way to
study disease processes, scanning drug candidates
for safety and effectiveness, or application to
regenerative medicine
 Examples include:
• Huntington’s disease
• Gaucher disease
• Type I juvenile diabetes
14.3 Genetically Modified Foods
 Transgenic plants are often referred to as either genetically
modified organisms (GMOs) or genetically modified (GM)
plants
 Often more widely accepted in the US than in other nations.
 Most likely over half of the food items you consumed today
contained an ingredient from a GMO. 60% to 70% of foods
in US supermarkets contain some transgenic plant material
 Products made from corn, soybeans, cottonseed and canola
oils most commonly contain transgenic ingredients
Foreign gene
incorporated
into a Ti
plasmid
Chromosomes inside
plant-cell nucleus
Bacterial
chromosome
1 The foreign gene is transferred into a plant cell. It
becomes incorporated into one of the plant’s chromosomes.
Fig. 14-9a, p. 319
2 The plant cell grows
and divides. Some of the
descendant cells give rise
to embryos that might go
on to develop into mature,
genetically engineered
whole plants, as below.
Embryo
Fig. 14-9b, p. 319
Transgenic Crop Plants can be made
Resistant to Herbicides and Disease
Fig. 14-10, p. 320
Transgenic Crop Plants can be made to
Enhance the Nutritional Value of Foods
 Golden rice contains increased levels of
vitamin A
Fig. 14-11, p. 320
Genetically Modified Crops
Approved in the US
Table 14-3, p. 320
Some Concerns About
Genetically Modified Organisms
 Are foods containing new proteins safe to eat?
 Is it safe to eat food carrying part of a viral gene that switches
on transgenes?
 Can insect resistance genes be transferred to weeds or wild
plants?
 Can these plants have an unforeseen detrimental effect on
the ecosystem?
 Will pesticide-resistant insects develop?
14.4 Transgenic Animals
as Models of Human Diseases
 Transgenic mice are a common model system
 Transfer of disease-causing human genes into mice
creates mice that are used to study the development
of human diseases and the effects of drugs and
other therapies
Transferring Genes into Mammals
 Microinjection of fertilized eggs
Fig. 14-12, p. 322
Mouse model for Huntington’s Disease (HD)
 HD mice are extremely useful as models of human
neurodegenerative disorders
• Used to study the progressive destruction of brain
structures in early disease stages
• Used to link changes in brain structure with changes
in behavior
• Used to screen drugs to improve symptoms or
reverse brain damage
Some Human Diseases
Studied in Animal Models
Table 14-4, p. 323
DNA Profiles
 Originally, minisatellites were used to make a DNA
fingerprint, now STRs are used to create a DNA
profile
 Short tandem repeat (STR)
• Short nucleotide sequences 2 to 9 base pairs long
found throughout the human genome that organized
into clusters of varying lengths
 DNA profile
• STR pattern used to identify individuals
DNA Profiles Can Be Made from
Short Tandem Repeats (STRs)
 STRs range from 2 to 9 base pairs in length
• CCTTCCCTTCCCTTCCCTTCCCTTCCCTTC
contains six repeats of the CCTTC sequence
 Repeat numbers vary between individuals
• A unique profile can be produced by analyzing
several STRs in a DNA sample
• In the US, a standard set of 13 STRs (CODIS) is
used to prepare a profile (for more info see:
http://www.fbi.gov/about-us/lab/codis/codis-and-ndis-fact-sheet)
A Sample DNA Profile from a Family
DNA Profiles Are Used in the Forensics and
Criminal Justice System
 DNA profiles are used in more than 10,000 criminal
cases per year.
 Analysis of DNA profiles combines probability
theory, statistics, and population genetics to
estimate how frequently an allele combination is
found in a population to calculate the probability that
a single person will have that combination
Control DNA
Size reference
Female cells
Semen
Size reference
Boyfriend
Control DNA
Suspect 2
Victim
Suspect 1
Control DNA
Size reference
Size reference
A DNA profile from a
criminal case
(Electrophoresis gel
of PCR products)
Fig. 14-14, p. 324
Exploring Genetics: Death of a Czar
 Forensics and several types of DNA evidence were
used to confirm that bones discovered in 1991
belonged to Czar Nicholas Romanov II, his wife, and
three of their five children who were killed during the
Russian Revolution
p. 325
14.6 Social and Ethical
Questions about Biotechnology
 Applications of recombinant DNA technology have developed
faster than public policy, legislation, and social norms
 Some issues that have arisen include:
• Should genetically modified foods be labeled?
• How much do animals suffer when used to make human
proteins or used in disease models?
• Who should have access to genetic information obtained from
genetic testing?
• Should we test for diseases for which there is no cure yet?