transfer of the - molekülce · transfer and dna synthesis completed o o o o o o . b) transfer of...

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Page 1: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F
Page 2: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

Transfer of the F factor

Page 3: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

Transfer of the Hfr F+ factor

Page 4: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

Excision of the F+ factor also occurs

spontaneously at low frequency.

Begin with Hfr cell containing F+.

Small section of host chromosome also

may be excised, creating an F’

plasmid.

F’ plasmid is named for the gene it

carries, e.g., F’ (lac)

Page 5: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

Interrupted

mating

experiment

Page 6: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

F- bacteria

2 Conjugation F plasmid

Mating Bridge

F+ bacteria

F plasmid

Page 7: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

2 Conjugation

F- bacteria

F plasmid

F+ bacteria

F plasmid

Mating Bridge

Page 8: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

Genetic map-results of interrupted E. coli mating experiment

Page 9: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F
Page 10: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F
Page 11: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F
Page 12: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F
Page 13: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F
Page 14: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

F+ factor (fertility factor)- a sophisticated plasmid

OriT, Origin of transfer

insertion sequences,

genes for own replication,

genes for own transfer

Page 15: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

Conjugation converts an F- to F+. Original F+ remains F+

Note: No host genes (in blue) transferred from F+ to F-

Page 16: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

To transfer host genes, need an Hfr strain

(high frequency)

Homologous

Recombination

here

One cell will have one or another of these

F+ to Hfr relative low frequency (~few %).

X-ray induces Hfrs. Why?,

Page 17: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F

Using an Hfr for gene transfer

Page 18: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F
Page 19: Transfer of the - Molekülce · Transfer and DNA synthesis completed O O o o O o . b) Transfer Of bacterial genes Hfr cell The cell Bacterial chromosome F factor Integration of F