Chapter 13 Chapter 13 - Biotechnology What is biotechnology? What is biotechnology used for? When...

Chapter 13

Chapter 13 - Biotechnology

What is biotechnology?

What is biotechnology used for?

When did biotechnology begin?

What are the basic techniques used in modern biotechnology?

How is biotechnology influencing human medicine?

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What is biotechnology?

Alteration of organisms, cells, or biological molecules to achieve specific practical goals

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What is biotechnology used for?

Production of pharmaceuticals

Production of commercial compounds

Agricultural improvements

Environmental cleanup

To better understand the functions and interactions of genes

-Advances in medical treatments

-Advances in agriculture

Diagnosis of genetic disorders

Forensics

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When did biotechnology begin?

Genetic manipulation/alteration of organisms has been occurring for over 10,000 years

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Historical vs. modern genetic manipulation

Historical – breeding

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Domestication of crops began ~10,000B.C.

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Genetic manipulation in the Brassica family

Europe & Mediterranean

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Teosinte – ancestor of corn (Mexico)

Cob selection

5000BC – 2cm

3000BC – 4cm

1000AD – 13cm

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What are the basic techniques of modern biotechnology?

Recombinant DNA technology-Moving small pieces of DNA between organisms

-Cloning Genes

-Isolating DNA from cells

-Restriction enzymes

-Polymerase Chain Reaction

-Gel electrophoresis

-DNA probes

-Genetic engineering

Viral mediated gene transfer

Gene Gun

Agrobacterium tumefaciens

DNA microarrays

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Recombinant DNA technology

Combining genes or parts of genes from different organisms

Transgenic – organisms containing “foreign” genes

Genetically modified organisms = GMOsGenetically modified organisms = GMOs

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Recombinant products

rBST and dairy products

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Is combining genes from different species inappropriately tampering with God’s creation?

DNA recombination occurs naturally1. Sexual reproduction

2. Bacterial transformation

3. Viral transfer of DNA

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Technologies used in cloning genes

1. Isolating DNA from cells

2. Restriction enzymes

3. Gel electrophoresis

4. Polymerase chain reaction

5. Hybridization

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Isolating DNA from cells

Cell membranes are lysed in detergent

Proteins are removed by precipitation

DNA is precipitated with alcohol

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Restriction enzymes cut DNA molecules

Restriction endonucleases (enzymes) cut DNA at specific short palindromic nucleotide sequences

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Agarose gel electrophoresis

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Gel electrophoresis separates DNA fragments by size

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Polymerase chain reaction (PCR)

Copies specific DNA sequences

A thermal cyclerA thermal cycler

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Polymerase chain reaction (PCR)

25-30 PCR cycles yield ~1 million copies of the DNA sample

Can be used on trace quantities of DNASaliva, hair follicle,

trace dried blood

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Hybridization – detection of specific DNA sequences (utilizes complementary base

pairing)

Southern blotting animation

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Forensic DNA analysis & hybridization

RFLP (Restriction Fragment Length Polymorphism) analysis

Began in 1985

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RFLP analysis and hybridization

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RFLP Case Study - OJ Simpson

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Hybridization & medicine: Diagnosis

RFLP analysis can be used in genetic disease diagnosis (sickle-cell anemia)

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Modern forensic DNA analysis

Based on the Polymerase Chain Reaction and STRs (Short tandem repeats)

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STRs and identity

Number of repeats varies (i.e. There are numerous STR “alleles”)

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PCR, STRs and identity

The greater the number of repeats, the longer the DNA pieces amplified by PCR

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What are the basic techniques of modern biotechnology?

Genetic engineering - Addition, deletion, or modification of genes in an organism

Genetic engineering is not limited to the genome of the organism being manipulated

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Genetic engineering & agriculture

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Genetic engineering in plants: Gene gun

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Genetic engineering in plants: Agrobacterium tumefaciens

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Plant biotechnology: Insect resistant crop plants

Bacillus thuringiensis (BT)

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Bacillus thuringiensis

BT spores form insecticidal crystal proteins

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Plant biotechnology: Herbicide resistant plants

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Genetic engineering of animals

Genzyme

GFP

Salmon growth hormone Salmon growth hormone gene engineered for gene engineered for constitutive (always on) constitutive (always on) expressionexpression

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How is biotechnology influencing human medicine?

Disease diagnosis and DNA arrays

Microarray construction link

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How is biotechnology influencing human medicine?

Correlating genes & disease

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Biotechnology & whole genome analysis

Whole genome arrays

~$300-500 each

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How is biotechnology influencing human medicine?

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Somatic Cell Gene TherapySomatic Cell Gene Therapy

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Germline Gene Therapy

Chapter 13American Journal of Medicine, Nov. 2003, p. 563

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Biotechnology is regulated

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Biotechnology concerns - allergenicity

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Biotechnology concerns

Gene “escape” via pollen