1. PowerPoint Presentation Materials to accompany
Genetics: Analysis and Principles
Robert J. Brooker
CHAPTER 19
BIOTECHNOLOGY
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2. INTRODUCTION
Biotechnology is broadly defined as technologies that involve the use of living organisms, or their products, to benefit humans
It is not a new topic
It began about 12,000 years ago when humans began to domesticate animal and plants for the production of food
Since the 1970s, molecular genetics has provided new, improved ways to make use of organisms to benefit humans
An organism that has integrated recombinant DNA into its genome is called transgenic
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3. 19.1 USES OF MICROORGANISMS IN BIOTECHNOLGY
Microorganisms are used to benefit humans in various ways
Molecular genetic tools are very important in influencing and improving our use of microorganisms
Overall, the use of recombinant microorganisms is an area of great research interest and potential
However, there are problems such as safety concerns and negative public perception
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4. The Genetic Engineering of Plants Is Easier Than That of Animals
Plant advantages:
1) they are easier to clone than animal cells (plant cells are totipotent: one cell can produce an entire plant);
2) they can be grown in vast fields which allows massive production of desired products;

5. Transgenic plants
Molecular biologists use the bacterium Agrobacterium tumefaciens which naturally infect plants to produce transgenic plants.
Molecular biologists can genetically engineer plants that can:
synthesize animal or plant proteins;
resist herbicides;
resist infection by plant viruses.

6. Gene Addition versus Gene Replacement
Cloned genes can be introduced into plant and animal cells
However, the gene will not be inherited stably if it does not become integrated into the host cell’s genome
This integration occurs by recombination
The introduction of a cloned gene into a cell can lead to one of two outcomes
Gene replacement
Gene addition
Refer to Figure 19.5
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7. If rendered inactive by mutation => gene knockout
Figure 19.5
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9. Production of Mice That Contain Gene Replacements
In bacteria and yeast, gene replacement is the common outcome
These have relatively small genomes, so homologous recombination occurs at a relatively high rate
In complex eukaryotes, gene addition is the norm
These have very large genomes, so homologous recombination is rare
Only 0.1% of the time
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10. This approach is shown in Figure 19.6
To produce mice with gene replacements, molecular biologists have resorted to trickery
Cells in which homologous recombination has occurred are preferentially selected
This approach is shown in Figure 19.6
The cloned gene is altered using two selectable markers
A neomycin-resistant gene (NeoR) is inserted into the center of the coding sequence of the target gene
A thymidine-kinase gene (TK) is inserted adjacent (not within) the target gene
TK renders cells sensitive to killing by a drug called gancyclovir
The modified target gene is then introduced into mouse embryonic cells which can be grown in the lab
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11. Use of Gene Replacements in Mice
Gene replacements were discussed in Figure 19.6
When a mouse is homozygous for an inactivated gene, this is called a gene knockout
The inactive mutant gene has replaced both copies of the normal gene
Gene replacements and gene knockouts have become powerful tools for understanding gene function
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12. The production of proteins from mammals is more advantageous than the from bacteria
1. Certain proteins are more likely to function properly when expressed in mammals
Post-translational modifications occur in eukaryotes
Degradation and misfolding occur in bacteria
The strategy for expressing human genes in animals is shown in Figure 19.13
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13. And use it to treat humans
Figure 19.13
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14. 19.4 DNA FINGERPRINTING
DNA fingerprinting is a technology that identifies particular individuals using properties of their DNA
It is also termed DNA profiling
The application of DNA fingerprinting to forensics has captured the most public attention
In addition, DNA fingerprinting can also be used to determine if two individuals are genetically related
For example, it is used routinely in paternity testing
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15. When subjected to DNA fingerprinting, chromosomal DNA gives rise to a series of bands on a gel
Refer to Figure 19.19
The order of bands is an individual’s DNA fingerprint
It is the unique pattern of these bands that makes it possible to distinguish individuals
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16. RFLPs as markers for disease-causing alleles
RFLP marker
DNA
Disease-causing
allele
Normal allele

17. Uses of DNA Fingerprinting
Within the past decade, the uses of DNA fingerprinting have expanded in many ways
In medicine, it is used identify different species of bacteria and fungi and also different strains of the same species
This is useful for appropriate antibiotic treatment
DNA fingerprinting is also used in forensics and relationship testing
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18. Male 2 does not have many of the child’s paternal bands
Therefore he cannot be the biological father
Male 1 has all the child’s paternal bands
The probability of this occurring by chance alone is very small
Therefore he is the biological father
Figure The use of DNA fingerprinting to establish paternity
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19. DNA fingerprints from a murder case
Defendant’s
blood (D)
Blood from
defendant’s
clothes
Victim’s
blood (V) D
Jeans
shirt V
4 g
8 g