Vertical Gene Transfer
Horizontal (Lateral) Gene Transfer
Characteristic of the
Bacterial Genome
How do bacteria introduce variety or diversity into their genome?
(2 ways!)
Mechanisms for
Acquiring Exogenous DNA
(3 ways!)
1. TRANSFORMATION
Transformation with DNA Fragments:
(Neisseria can do this naturally)
Transformation with PLASMIDS:
2. TRANSDUCTION
Bacteriophage or Phage
BASIC steps of the Lytic Cycle of Phage
GENERALIZED
TRANSDUCTION
Lysogeny
(an alternative to lyses/lytic)
Plaque Assay
Phage Therapy
3. CONJUGATION
Gram Positive (+)
Bacterial Conjugation
Gram Negative (-)
Bacteria
CONJUGATION
mediated by?
example?
HFr?
F+
F-
Hfr (high frequency recombinant)
Will the F- likely remain F- or become F+ after conjugation with an F+ HFr cell?
GENOMIC ISLANDS
Pathogenicity islands
CONCLUSION
SIGNIFICANCE