Document 7280776

Download Report

Transcript Document 7280776

Gene Transfer: How New Strains Arise and Biotechnology
What special mechanisms allow bacteria to swap genes between cells?
•
Gene Transfer and Recombination
•
•
Donor and recipient; recombination
Prokaryotic Gene Transfer
•
Transformation
•
Transduction: Bacteriophage transfer
•
Conjugation
• Plasmids: F factors, R factors
•
Eukaryotic Gene Recombination
•
Viral Gene Changes
•
Application of DNA Biotechnology
•
•
Fast, inexpensive, ethical methods
Strategies of Gene Manipulation/Analysis
•
Recombinant DNA and Cloning
• Restriction enzymes
• Steps of Cloning the Insulin Gene
•
Making many Copies: Polymerase Chain Reaction
•
DNA Fingerprinting
•
Genetic sequencing
Recombination Produces New Genotypes
Donor
DNA
Recipient DNA
Genotype: abcde
Genotype: aBcde
(now has a new phenotype
or ability, like being able to
use a sugar it could not
before)
Figure 8.25
Transformation: Absorption of Free DNA
In a lab setting, many
bacterial species are not
“competent” to take up donor
DNA. They are incubated in
CaCl2 to make them
competent and then heat
shocked so they will suck up
DNA fragments from the
medium.
Figure 8.24
Plasmids: Autonomously Replicating Extrachromosomal DNA
Fertility (F) factor is a plasmid that can
direct the formation of a sex pilus and
DNA transfer by conjugation
Conjugation: Simple F+ to F- Transfer
Figure 8.27a
Conjugation: Creation of an Hfr Cell
Figure 8.27b
Conjugation: Hfr to F- cell
Figure 8.27c
Transduction
Phage protein coat
Bacterial
chromosome
Recombinant
Bacterial
DNA
Donor
bacterial
DNA
Phage
DNA
Recipient cell
Recipient
bacterial
DNA
Recombinant cell
Figure 8.28
Gene Transfer: How New Strains Arise and Biotechnology
What special mechanisms allow bacteria to swap genes between cells?
•
Gene Transfer and Recombination
• Donor and recipient; recombination
•
Prokaryotic Gene Transfer
• Transformation
• Transduction: Bacteriophage transfer
• Conjugation
• Plasmids: F factors, R factors
•
Eukaryotic Gene Recombination
•
Viral Gene Changes
•
Application of DNA Biotechnology
• Fast, inexpensive, ethical methods
•
Strategies of Gene Manipulation/Analysis
• Recombinant DNA and Cloning
• Restriction enzymes
• Steps of Cloning the Insulin Gene
• Making many Copies: Polymerase Chain Reaction
• DNA Fingerprinting
Genetic Recombination In Eukaryotes: Crossing Over
• Prophase I of
Meiosis
Figure 8.23
Double Infection By Two Viruses Can Produce a New Novel Virus By Recombination
(In eukaryotes, is this how new recombinations of influenza viruses arise)
Gene Transfer: How New Strains Arise and Biotechnology
What special mechanisms allow bacteria to swap genes between cells?
•
Gene Transfer and Recombination
• Donor and recipient; recombination
•
Prokaryotic Gene Transfer
• Transformation
• Transduction: Bacteriophage transfer
• Conjugation
• Plasmids: F factors, R factors
•
Eukaryotic Gene Recombination
•
Viral Gene Changes
•
Application of DNA Biotechnology
• Fast, inexpensive, ethical methods
•
Strategies of Gene Manipulation/Analysis
• Recombinant DNA and Cloning
• Restriction enzymes
• Steps of Cloning the Insulin Gene
• Making many Copies: Polymerase Chain Reaction
• DNA Fingerprinting
Biotechnology/DNA Technology: Genetic Engineering Scheme
Advantages &
Disadvantages
Figure 9.1.1
Restriction Enzymes Recognize and Cut at Recognition Sites
Figure 9.2
Vector: Something That Can Carry in New DNA and Be Stable in the Cell
Should have several restriction enzyme sites
Figure 9.3
Gene Transfer: How New Strains Arise and Biotechnology
What special mechanisms allow bacteria to swap genes between cells?
•
Gene Transfer and Recombination
• Donor and recipient; recombination
•
Prokaryotic Gene Transfer
• Transformation
• Transduction: Bacteriophage transfer
• Conjugation
• Plasmids: F factors, R factors
•
Eukaryotic Gene Recombination
•
Viral Gene Changes
•
Application of DNA Biotechnology
• Fast, inexpensive, ethical methods
•
Strategies of Gene Manipulation/Analysis
• Recombinant DNA and Cloning
• Restriction enzymes
• Steps of Cloning the Insulin Gene
• Making many Copies: Polymerase Chain Reaction
• DNA Fingerprinting
Genetic Engineering Involves Insertion of a Gene on a Plasmid
Safety Issues and Ethics
• Avoid accidental release of supergerms
• Genetically modified crops must be safe for
consumption and for the environment
• Who will have access to an individual's genetic
information?
• Do we have a right to move genes around, creating
new life forms (i.e. “playing God”)?
Gene Transfer: How New Strains Arise and Biotechnology
What special mechanisms allow bacteria to swap genes between cells?
•
Gene Transfer and Recombination
•
•
Donor and recipient; recombination
Prokaryotic Gene Transfer
•
Transformation
•
Transduction: Bacteriophage transfer
•
Conjugation
• Plasmids: F factors, R factors
•
Eukaryotic Gene Recombination
•
Viral Gene Changes
•
Application of DNA Biotechnology
•
•
Fast, inexpensive, ethical methods
Strategies of Gene Manipulation/Analysis
•
Recombinant DNA and Cloning
• Restriction enzymes
• Steps of Cloning the Insulin Gene
•
Making many Copies: Polymerase Chain Reaction
•
DNA Fingerprinting
•
Genetic sequencing
Polymerase Chain Reaction: DNA Replication in a Test Tube
Exponential Increase in the Number of DNA Molecules each Cycle
Gene Transfer: How New Strains Arise and Biotechnology
What special mechanisms allow bacteria to swap genes between cells?
•
Gene Transfer and Recombination
•
•
Donor and recipient; recombination
Prokaryotic Gene Transfer
•
Transformation
•
Transduction: Bacteriophage transfer
•
Conjugation
• Plasmids: F factors, R factors
•
Eukaryotic Gene Recombination
•
Viral Gene Changes
•
Application of DNA Biotechnology
•
•
Fast, inexpensive, ethical methods
Strategies of Gene Manipulation/Analysis
•
Recombinant DNA and Cloning
• Restriction enzymes
• Steps of Cloning the Insulin Gene
•
Making many Copies: Polymerase Chain Reaction
•
DNA Fingerprinting
•
Genetic Sequencing
DNA Fingerprinting Generates Banding Patterns Unique to Individuals
1. Collect cells
2. Extract DNA
3. Cut the DNA in
fragments using
the same restriction
enzyme
4. Separate the
fragments using gel
electrophoresis
Figure 12.12
Gene Transfer: How New Strains Arise and Biotechnology
What special mechanisms allow bacteria to swap genes between cells?
•
Gene Transfer and Recombination
•
•
Donor and recipient; recombination
Prokaryotic Gene Transfer
•
Transformation
•
Transduction: Bacteriophage transfer
•
Conjugation
• Plasmids: F factors, R factors
•
Eukaryotic Gene Recombination
•
Viral Gene Changes
•
Application of DNA Biotechnology
•
•
Fast, inexpensive, ethical methods
Strategies of Gene Manipulation/Analysis
•
Recombinant DNA and Cloning
• Restriction enzymes
• Steps of Cloning the Insulin Gene
•
Making many Copies: Polymerase Chain Reaction
•
DNA Fingerprinting
•
Genetic sequencing
Genetic Sequencing
• Comparing the
nucleotide
sequences of rRNA
genes(the 16S type)
in prokaryotes (and
eukaryotes) has
helped show
evolutionary
relatedness
• Used to separate
prokaryotes and
eukaryotes into 3
Domains in the late
1980s
Gene Transfer: How New Strains Arise and Biotechnology
What special mechanisms allow bacteria to swap genes between cells?
•
Gene Transfer and Recombination
•
•
Donor and recipient; recombination
Prokaryotic Gene Transfer
•
Transformation
•
Transduction: Bacteriophage transfer
•
Conjugation
• Plasmids: F factors, R factors
•
Eukaryotic Gene Recombination
•
Viral Gene Changes
•
Application of DNA Biotechnology
•
•
Fast, inexpensive, ethical methods
Strategies of Gene Manipulation/Analysis
•
Recombinant DNA and Cloning
• Restriction enzymes
• Steps of Cloning the Insulin Gene
•
Making many Copies: Polymerase Chain Reaction
•
DNA Fingerprinting
•
Genetic sequencing