Chapter 19

Question 1

Genetic engineering

Answer 1

–Alteration of organism’s genome using recombinant DNA technologies to add or remove gene from genome
–Produces genetically modified organisms (GMOs)

Question 2

Biotechnology

Answer 2

–Utilizing living organisms to create a product or process that helps improve life for humans or other organisms

Question 3

Genetically Modified Organisms

Answer 3

Biopharming
–Production of proteins in genetically modified plants and animals
Biopharmaceutical products
–Recombinant proteins
–Therapeutic proteins that treat disease
Table19.1
–Important recombinants synthesized in transgenic bacteria, plants, yeast, and animals

Question 4

Insulin production in bacteria

Answer 4

insulin production in bacteria
- therapeutic proteins can be produced by introducing human genes to bacteria
Humulin
- synthetic human insulin was originally produced in bacteria
- insulin regulates glucose metabolism

Question 5

Transgenic Animal Hosts and Pharmaceutical Products

Answer 5

Bacteria are unable to process and correctly modify many eukaryotic proteins.
- Cannot add carbohydrates or phosphorylate-like eukaryotic organisms
Solution:
- Many biopharmaceuticals are now produced in eukaryotic hosts.
- Bioreactors or biofactories: living factories, such as a herd of goats or cows

Biopharmaceutical products synthesized in transgenic animals include
–Human protein alpha 1-antitrypsin: cloned into vector at site adjacent to sheep promoter sequence—specifically activates transcription in mammary tissue
(Milk containing high concentrations of functional human alpha-antitrypsin was produced)
–Antithrombin; clotting protein—world’s first drug extracted from goat’s milk

Question 6

Recombinant DNA Approaches for Vaccine Production

Answer 6

1. Vaccines
   –Stimulate immune system to produce antibodies against disease-causing organisms
   Traditional vaccines used:
2. Inactivated vaccines: prepared from killed samples of infectious virus or bacteria
3. Attenuated vaccines
   - live viruses or bacteria that can no longer reproduce but can cause mild form of disease
4. Subunit Vaccines
   –Surface proteins from virus or bacterium developed by genetic engineering
   ex: Hepatitis B virus–Causes liver damage and cancer–Surface protein cloned into yeast expression vector → purified from yeast →packaged for use as vaccine
   ex: Gardasil: vaccine that provides immunity against humanpapillomavirus (HPV)

Question 7

Genetic Engineering of Plants Has Revolutionized Agriculture

- selective breeding

Answer 7

• Selection and breeding of naturally occurring or mutagen-induced variants
• Technique utilized by farmers for generations
• Manipulates genetic makeup of plant and animal to enhance food production

Question 8

Agricultural Biotechnology

Answer 8

Agricultural biotechnology
–Introduces insect resistance, herbicide resistance, or nutritional characteristics into farm plants and animals
GMOs: genetically modified organisms
–Includes genetically modified foods
ex: transgenic crop plants)
ex: Alfalfa, corn, rice, potatoes, tomatoes, tobacco, wheat, and cranberries

Question 9

Transgenic crops

Answer 9

Several reasons for generating transgenic crops include
– Improving growth characteristics and yield of culturally valuable crops
–Increasing nutritional value of crops
–Providing crop resistance against insect and viral pests, drought, and herbicides
–Providing crops for ethanol production and biofuel
–Providing sustainable sources of energy

Question 10

Transgenic Animals Serve Important Roles in Biotechnology

Answer 10

Transgenic animals
– Created for research purposes to study gene function
Examples of transgenic animals
–Oversized mice containing human growth hormone transgene
–Transgenic Atlantic salmon
–Transgenic cows (Generated cows that possessed lysostaphin gene which produces protein that cleaves S. aureus cell wall)

Question 11

Genetic Engineering and Genomics Are Transforming Medical Diagnosis
- gene testing

Answer 11

Gene testing
–One of the first successful applications of recombinant DNA technology
–Currently, more than 900 gene tests in use
–DNA mutations associated with single-gene diseases detected
(Sickle-cell anemia, cystic fibrosis, Huntington disease, hemophilias, muscular dystrophies)

Question 12

Uses of gene tests

Answer 12

–Perform prenatal diagnosis of genetic diseases.
–Identify carriers.
–Predict future development of diseases in adults.
–Confirm diagnosis of disease detected by other methods.
–Identify genetic diseases in embryos created by in vitro fertilization.

Question 13

prenatal genetic testing

Answer 13

–Many genetic disorders are diagnosed prenatally using cytogenetic, biochemical, and recombinant DNA testing.
–Samples are obtained from amniocentesis
–Figure 19-5
–Fetal cell sorting of fetal cells from maternal blood may eventually replace amniocentesis.

Question 14

Genetic test based on restriction enzymes

Answer 14

– RFLP: restriction fragment length polymorphism

(Utilized in diagnosis of sickle-cell anemia)

Question 15

Genetic Analysis Using DNA Microarrays and Genome Scans

Answer 15

• RFLP analysis can only detect one or a few mutations of known genes.
• DNA microarrays (DNA or gene chips) can generate up to 500,000 different fields, each representing a different DNA sequence.
• Figure 19-9 and Figure 19-10

Question 16

Genotyping Microarrays

Answer 16

–Used to detect mutations in specific genes
–Probes on genotyping microarray consist of short oligonucleotides.
–Scan gene of interest looking for mutations at each position in gene.
Example: p53 gene—associated with majority of human cancers

Question 17

Genetic Analysis Using Gene-Expression Microarrays

Answer 17

Gene-expression microarrays
–Revealed that certain cancers have patterns of gene expression
–Patterns correlate with factors
 1. Stage of cancer
2. Clinical course 
3. Response to treatment

Question 18

Individual genome sequencing

Answer 18

Utilized in medical clinics
–Changing ways scientists and physicians evaluate a person’s genetic information 
–Provides insight into the genetics of:
Alzheimer disease
Proteus syndrome
Anorexia
Many other diseases

Question 19

Single-cell sequencing

Answer 19

• We can now sequence the genome from a single cell.
• Involves isolating DNA from single cell and executing whole-genome amplification
• Produces sufficient DNA to be sequenced

Question 20

Genome-Wide Association Studies Identify Genome Variations That Contribute to Disease

Answer 20

Genome-wide association studies (GWAS)
–Quest to identify genes that influence disease
–Result: 700 publications linking 3000 genetic variations to about 150 traits
How GWAS are carried out
–Compares genomes of thousands of unrelated individuals with particular disease to those without disease
–Identifies variations that confer risk of developing disease (Figure 19-12)

Question 21

Genomics Leads to New, More Targeted Medical Treatment Including Personalized Medicine

Answer 21

Genomic technologies are changing medical diagnosis

–Allow scientists to manufacture abundant and effective therapeutic proteins

Question 22

Pharmacogenomics

Answer 22

– Designed to lead to more specific, effective, and customized drugs
– Drugs designed to complement each person’s individual genetic makeup

Question 23

Genetherapy

Answer 23

• Therapeutic technique—aims to transfer normal genes into patient’s cells
• Specific genes transferred into mammalian cells to treat genetic disorders
• Normal genes transcribed and translated into functional gene products to bring about normal phenotype

Question 24

Genetic Engineering, Genomics, and Biotechnology Create Ethical, Social, and Legal Questions

Answer 24

Genetic Testing and Ethical Dilemmas
Recombinant DNA and genomic technologies
–Identify genes
–Diagnose and treat genetic disorders
–Produce commercial and pharmaceutical products.
–Solve crimes.
(Applications of knowledge gained raise ethical, social, and legal issues)

Question 25

Ethical, Legal, andSocialImplications (ELSI) Program

Answer 25

Established as adjunct to Human Genome Project Addresses issues such as

• Confidentiality of genetic information and implications for medical practice
• Genetic counseling
• Reproductive decision making

Question 26

DTC testing

Answer 26

Direct-to-consumer (DTC) genetic tests are offered by many companies.
–Over 1900 diseases can be tested for.
–Saliva sample or cheek swab is mailed to company for testing.
–Tests are not FDA regulated; questions about accuracy arise.

Question 27

DNA and Gene Patents

Answer 27

Intellectual property (IP) rights
–Debated as aspect of ethical implications of genetic engineering, genomics, and biotechnology
–Patents on intellectual property (isolated genes, new gene constructs, recombinant cell types, GMOs)
(Are lucrative for patent holder)
(May also pose ethical and scientific problems)

Question 28

Newborn Sequencing

Answer 28

Genomic Sequencing and Newborn Sequencing Disorders Program
–Program is underway to sequence exomes of more than 1500 babies.
–Early screening of PKU and many other crucial genetic disorders may be required by law in the future.