MICROBIAL GENETICS

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MICROBIAL GENETICS CONJUGATION
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MICROBIAL GENETICS - CONJUGATION
Male, Fertility Factor, Donor Female, absence of
F Factor, Recipient F Male, Sex Pili,
Conjugation Bridge, Origin of Transfer, Nicking
at oriT, Transfer of Single Strand, Complementary
strand synthesis in male and female Hfr Male
(High Frequency of Recombination), Integration,
Homologous Recombination, Selection of
recombinants F' Male, Illegitimate
recombination, Partial diploids
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CONJUGATION - MATING OF MALE AND FEMALES E. COLI
MALES FERTILITY FACTOR F PLASMID 100,000
BASE PAIRS MALE CHARACTERISTICS CONTACT
WITH FEMALE DNA DONATION FEMALES F
- DNA RECIPIENT ABSENCE OF F FACTOR F
FACTOR - DOUBLE STRAND DNA
IS2
INSERTION SEQUENCE 1
TRANSFER GENES
F
REPLICATION GENES
oriT ORIGIN OF TRANSFER
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F MALE
F PILUS
BINARY FISSION
CHROMOSOME AND F FACTOR DUPLICATED
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F FACTOR TRANSFER F x F - F AND
F
F
F -
NICK F AT oriT TRANSFER ONE STRAND
CONJUGATION BRIDGE
NEW SYNTHESIS
F
F
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HFR HIGH FREQUENCY RECOMBINANT MALES TRANSFER
CHROMOSOME FRAGMENTS

• FORMING HFR
• F INTEGRATES INTO CHROMOSOME
• F BECOMES HFR

oriT
IS2
F MALE
PRO
LAC
IS2
HOMOLOGOUS RECOMBINATION BETWEEN IS2
oriT
IS2
IS2
HFR MALE
PRO
LAC
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• HFR x F - RECOMBINANTS
• HFR PRO STRS x F - PRO- STRR
• RECOMBINANT PRO STRR

PROLINE
F -
NEW SYNTHESIS
HFR
CONJUGATION BRIDGE BREAKS
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CONSIDER RECIPIENT CELL ONLY
HOMOLOGOUS RECOMBINATION - TWICE LEFT AND RIGHT
OF MUTATION
LINEAR FRAGMENT DEGRADATION
PRO STR-R F- RECOMBINANT
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DEMONSTRATION
GLUCOSE AND STREPTOMYCIN
108 HFR PRO STR-S
108 F- PRO- STR-R
MIX 108 HFR 108 F-
PRO STR-R RECOMBINANTS
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HFR CAN EXCISE F FACTOR PRECISELY TO REGENERATE
F MALE
IS2
IS2
HFR
IS2
IS2
HOMOLOGOUS RECOMBINATION BETWEEN IS2's
IS2
F MALE
IS2
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F' MALE F PLUS CHROMOSOME GENE(S)
PRO
HFR
LOOPING
STR-S
PRO
ILLEGITIMATE RECOMBINATION
DELETION
PRO
F' MALE
STR-S
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F ' MATING F ' x F - F ' NEW F '
PRO
PRO
PRO-
STR-S
STR-R
F' STR-S PRO
F - PRO- STR-R
PRO
PRO
PRO-
STR-S
STR-R
NEW F' MALE PARTIAL DIPLOID
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F' TRANSFER IN LAB
GLUCOSE PLUS STREPTOMYCIN
MIXTURE OF F' PRO STR-S F - PRO- STR-R YIELDS
108 F' PRO (ON F FACTOR) PRO DELETION (ON
CHROMOSOME) STR-S
108 F - PRO- STR-R
F' PRO / PRO- STR-R