Ch. 20: DNA Technology

1
Ch. 20 DNA Technology

• Dolly/cloning humans?
• Curing diseases?
• Regrowing limbs/spinal cords/ and other organs
• Identifying those that break the law
• Feed the world

2
Why is it all possible now and not before?

• We have biochemical tools that allow construction
  of recombinant DNA.
• We have methods for purifying DNA molecules and
  proteins of interest.
• We can use vectors for carrying recombinant DNA
  into cells and replicating it.
• We have techniques for determining nucleotide
  sequences of DNA molecules.

3
DNA Cloning

• How do bacteria acquire new DNA?
• Transformation
• Conjugation
• Transduction
• How are bacteria used to clone genes for
  biotechnology?
• (fig. 20.1)

4
Cloning human genes

• What are restriction enzymes?
• They occur naturally in bacteria for
  protection.
• How do they do it?
• Restriction sites/restriction sequence
• Sticky ends
• Restriction fragments/DNA fragments
• DNA ligase
• OUTCOME recombinant DNA
• (fig. 20.3)

5
How do we know we are cloning the right gene?

• Nucleic acid probes (fig. 20.4)

6
Problem

• Eukaryotic genes may be too large to clone easily
  because they contain long noncoding regions
  (introns).
• Solution (fig. 20.5)
• cDNA

7
What if you had just a little DNA to test...

• PCR
• procedure
• uses

8
Restriction fragment analysis

• Gel electrophoresis
• procedure
• uses
• DNA fingerprint
• Hybridization
• RFLPs

9
Mapping of entire genomes

• 1. Genetic (linkage) mapping
• 2. Physical mapping ordering of DNA fragments
• 3. Sequencing the DNA
• 4. Analyzing the DNA sequences
• 5. Studying gene expression
• 6. Determining gene function

10
Ethical Implications..

• What are the possibilities?
• Pros and Cons
• (video Genetic Engineering)