Chapter 16 Gene Technology. Focus of Chapter u An introduction to the methods and developments in: u...
Transcript of Chapter 16 Gene Technology. Focus of Chapter u An introduction to the methods and developments in: u...
Focus of Chapter
An introduction to the methods and developments in: Recombinant DNA Genetic Engineering Biotechnology
Methods to Know
1. Bacteria Transformation2. Restriction Enzymes3. cDNA4. DNA Sequencing5. PCR6. RFLP
Genetic Engineering
The direct manipulation of genes for practical purposes.
Ex: Using E. coli to produce human insulin.
Biotechnology
The use of living organisms or their components to perform practical tasks.
Ex: the use of bacteria to digest oil spills.
Plasmids
Used extensively in Biotechnology and Recombinant DNA.
Serve as a “vehicle” for transporting genes.
Steps for Plasmid Use
1. Get the DNA for the trait.
2. Insert DNA into the plasmid.
3. Bacterial Transformation.
4. Identification of the new trait.
Restrictive Enzymes
Cut DNA at specific nucleotide sequences called “restriction sites”.
Used to "cut and splice" DNA.
Obtained from bacteria. Ex. EcoRI and Hind III
Insertion
Placing foreign DNA into a plasmid.
Open plasmid with enzymes to create “sticky ends”.
Splice the new DNA and plasmid together.
Identification
Screening the altered cells for the desired gene.
Ex: Antibiotic sensitivity or the expression of a “new” trait (color, glowing etc.).
Comment Gene can’t be above a certain
size or a plasmid won’t work. Use other tools like YACS and BACS (artificial chromosomes).
mRNA must not need splicing to remove introns.
DNA Sources
1. Organism - use a section of their chromosome.
2. cDNA - Complementary DNA - created copy of DNA from the mRNA transcript to avoid introns. Uses reverse transcriptase.
Application
DNA sequence is read base by base.
By sequencing overlapping pieces of chromosomes, the entire genome of an organism can be read. (chromosome walking)
PCR
Polymerase Chain Reaction Method for making many
copies of a specific segment of DNA.
Also called “DNA Amplification”.
PCR - Method
1. Separate strands by heating (denature the DNA).
2. Cool slightly.
3. Build new strand from primers and nucleotides.
4. Repeat.
Importance - PCR
Can amplify any DNA with as little as one original copy.
Very useful in a variety of techniques and tests.
RFLP Analysis
Restriction Fragment Length Polymorphisms.
Method for detecting minor differences in DNA structure between individuals.
Common in DNA fingerprinting
Method
1. Digest DNA with restrictive enzymes.
2. Separate pieces by Gel Electrophoresis
3. Identify sequences with probes.
Result
Patterns of DNA markers or DNA fingerprint
Markers are inherited in a Mendelian pattern and can show relationshiops (Pedigree studies).
Forensic Uses
DNA fingerprints for crime solving – used in every TV crime show
DNA identification records – standard for the military
Comments
Links suspect bodily to the crime scene, but doesn’t prove they committed the crime.
Results take MUCH longer than on TV shows.
Analysis of old evidence is reversing some sentences.
Agricultural Uses
1. Animals Increased milk production Increased feed utilization Increased meat production
Agricultural Uses
2. Plants Herbicide resistance Retard spoilage of fruits Insect resistance – BT corn Nitrogen-Fixation ability
Genetically Modified Organism or GMO
Produced by direct genetic manipulation, not traditional breeding practices.
FDA just approved sale of GMO animal products for human consumption.
Bioethics concerns
Future Of DNA Technology
Cloning of higher animals. Stem Cells - growth of
replacement tissues and organs. Gene therapy to correct DNA
defects. ?
Summary Know the basics of some of
the DNA technology techniques.
Know: Bacterial transformation lab How Gel electrophoresis works Restriction enzymes