Transcript Chapt21 Lecture 13ed Pt 4

Human Biology
Sylvia S. Mader
Michael Windelspecht
Chapter 21
DNA Biology
and Technology
Lecture Outline
Part 4
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21.3 DNA Technology
Biotechnology products:
Transgenic plants
• Important uses
– Produce human proteins in their seeds such
as hormones, clotting factors, and
antibodies
– Plants resistant to herbicides
– Plants resistant to insects
– Plants resistant to frost
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21.3 DNA Technology
Genetically engineered plants
• Corn, soybean, and cotton plants are commonly
genetically altered.
• In 2011, 94% of the soybeans and 80% of the
corn planted in the United States had been
genetically engineered.
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a. Herbicide-resistant soybean plants
Figure 21.19 Genetically engineered plants.
b. Nonresistant potato plant
c. Pest-resistant potato plant
(all): Courtesy Monsanto
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21.3 DNA Technology
Biotechnology products:
Transgenic plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Transgenic Crops of the Future
Improved Agricultural Traits
Disease-protected
Wheat, corn, potatoes
Herbicide-resistant
Wheat, rice, sugar beets, canola
Salt-tolerant
Cereals, rice, sugarcane
Drought-tolerant
Cereals, rice, sugarcane
Cold-tolerant
Cereals, rice, sugarcane
Improved yield
Cereals, rice, corn, cotton
Modified wood pulp
Trees
Improved Food Quality Traits
Fatty acid/oil content
Corn, soybeans
Protein/starch content
Cereals, potatoes, soybeans, rice, corn
Amino acid content
Corn, soybeans
Salt-intolerant
Salt-tolerant
b(both): Courtesy Eduardo Blumwald
Figure 21.20 Genetically engineered plants for desirable traits.
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21.3 DNA Technology
Biotechnology products:
Transgenic animals
• Gene is inserted into the egg that when fertilized
will develop into a transgenic animal
• Current uses
– ____________: production of pharmaceuticals in
the milk of farm animals
– ____________: includes fish, cows, pigs, rabbits,
and sheep
– Mouse models: the use of mice for various gene
studies
– ___________________: pigs can express human
proteins on their organs making it easier to
transplant them into humans
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21.3 DNA Technology
Production of a transgenic animal
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human gene
for growth
hormone
microinjection of human gene
donor of egg
development within a host goat
human growth
hormone
Transgenic goat produces
human growth hormone.
milk
fusion of enucleated
eggs with 2n
transgenic nuclei
donor of eggs
development within a host goat
Figure 21.21 Production
of a transgenic animal.
milk
Cloned
transgenic
goats produce
human growth
hormone.
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21.4 Genomics and Gene Therapy
What did we learn from the Human
Genome Project (HGP)?
•
The human genome consists of about 3 billion
bases and 25,000 genes.
•
The human genome was sequenced in _____.
•
There are many polymorphisms, or small
regions of DNA that vary among individuals
identified.
•
Genome size is _________________ with the
number of genes or complexity of the
organisms.
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21.4 Genomics and Gene Therapy
What is the next step in the HGP?
•
Functional genomics
•
•
•
Understanding how the 25,000 genes function
Understanding the function of _____________
(25% of DNA is comprised of these regions)
Comparative genomics
•
•
•
Help understand how species have evolved
Comparing genomes may help identify base
sequences that cause human illness
Help in our understanding of gene regulation
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21.4 Genomics and Gene Therapy
Functional and comparative genomics
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a.
b.
c.
a (top): © Digital Vision/Getty RF; a (bottom): © Getty RF; b (left): © Digital Vision/GettyRF; b (right): © The McGraw-Hill
Companies, Inc. Bob Coyle, photographer; c (left): © Digital Vision/Getty RF; c (right): © Getty RF
Figure 21.22 Functional and comparative genomics between chimpanzees and humans.
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21.4 Genomics and Gene Therapy
New endeavors
•
Proteomics – the study of the structure,
function, and interactions of cell proteins
•
This can be difficult to study because:
•
•
•
•
protein concentrations differ greatly between
cells.
protein location and concentration interactions
differ from minute to minute.
understanding proteins may lead to the
discovery of better drugs.
Bioinformatics – the application of computer
technologies to study the genome
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21.4 Genomics and Gene Therapy
How can we modify a person’s
genome?
•
Gene therapy – insertion of genetic material
into human cells to treat a disorder
–
–
•
In _______ therapy, cells are removed from the
body for treatment, and then reintroduced back
into the body.
In _______ therapy, the vector is introduced
directly into the body.
Gene therapy has been most successful in
treating cancer.
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21.4 Genomics and Gene Therapy
Gene therapy
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homologous
chromosomes
1. Remove bone
marrow stem cells.
2. Use retroviruses
to bring the normal
gene into the bone
marrow stem cells.
retrovirus
defective gene
viral recombinant DNA
4. Return genetically
engineered cells
to patient.
reverse transcription
viral
recombinant
RNA
normal gene
viral recombinant RNA
3.Viral recombinant
DNA carries normal
gene into genome.
normal gene
Figure 21.23 Gene therapy.
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