26, BIS101
April 2011
Bacterial Genetics II
Strain
A
B
C
D
Does it form
a conjugation
tube?
yes
yes
yes
no
glucose
y es
y es
y es
no
Growth in minimal media containing:
lactose glucose/met glucose/met/str lactose/met/str
yes
yes
no
no
yes
yes
no
no
yes
yes
no
no
no
no
yes
yes
Growth in media containing:
Mating
AXD
BXD
CXD
glucose/str
yes
no
no
From Transduction Handout
glucose/met/srp
/str
yes
yes
yes
lactose/str
no
no
no
lactose/met/str
no
no
yes
Are
these cells
Donors?
yes
yes
no
Transformation
Bacteriaphage
Bacteriaphage
Bacteriaphage
QuickTime and a
decompressor
are needed to see this picture.
Bacteriaphage
Bacteria phage T4
1.7 X105 bp genome encodes about 300 gene products
(E. coli = 4.6 X106 bp)
Generalized Transduction
Co-transduction
DNA
Qualities necessary for the structural features of the genetic
material:
1. Must informational have content (to encode for proteins)
2. Must allow for faithful replication during each cell division
3. Must have physical and chemical stability
3. Must be able to change (e.g. by mutation- more in Chapter 14).
DNA is the Genetic Material
Griffith, 1928
DNA is the Genetic Material
Avery, MacLeod and McCarty, 1944
DNA is the Genetic Material
Hershey-Chase, 1952
Rosalind Franklin
Franklins X-ray diffraction pattern of DNA
James Watson and Francis Crick
1962 Nobel Prize in Physiology or Medicine
The Structure of DNA
Qualities necessary for the structural features of the genetic
material:
1. Must have informational content (to encode for proteins)
2. Must allow for faithful replication during each cell division
3. Must have physical and chemical stability
3. Must be able to change (e.g. by mutation- more in Chapter 14).