Se ha denunciado esta presentación.
Utilizamos tu perfil de LinkedIn y tus datos de actividad para personalizar los anuncios y mostrarte publicidad más relevante. Puedes cambiar tus preferencias de publicidad en cualquier momento.
1
SUBMITTED BY HAFSA ARSHAD
ROLL NO: BBOF17M006
Bs.6th Regular
SUBMITTED TO: Dr. AMIN ULLAH SHAH
DEPARTMENT OF BOTANY
UNIVER...
HISTORY
J. Lederberg and E. Tatum demonstrated
the transfer of genes between bacteria
that depends on
– direct cell to cel...
Bacterial Conjugation
Bacterial conjugation is the transfer of genetic material
between bacterial cells by direct cell-to-...
TERMINOLOGY
The Donor
F+
Fertility factor
Contains genetic
material for gene
exchange
“ Male cell
The Recipient
F-
No fert...
Bacterial Plasmids
• Small, autonomously replicating DNA
molecules
– can exist independently from host
chromosome
– can in...
15
• F factors contain the information for
formation of sex pilus
– attach F+ cell to F- cell for DNA transfer
during bact...
1- Cell – Cell contact
Formation of “sex pilus” or
F-bridge between cells
Attachment Via
Pilli
2- MOBILIZATION
 Target DNA is replicated
in F+
 Genetic transfer of
ssDNA to F-
Genetic Transfer of ssDNA
F+ x F-
Mating
• A copy of the F factor is transferred to the recipient and
does not integrate into the host chromosome
• ...
HFr Conjugation
• Donor HFr cell has F factor integrated into
its chromosome
• Donor genes are transferred to recipient
ce...
3- DNA SYNTHESIS
 Complementary strands of
DNA are replicated in both
F- and F+
 Target DNA is incorporated
into F- geno...
4- SEPARATION
 Cells separate
 Form two F+ cells with
completed recombinant
plasmids
 Both serve as donor cells for
fur...
F’ Conjugation
• Result when the F factor
incorrectly leaves the host
chromosome
• Some of the F factor is left
behind in ...
Thanks
hafsaranjha.botanist@gmail.com
Bacterial conjugation
Próxima SlideShare
Cargando en…5
×

Bacterial conjugation

bacterial conjugation genetic transfer transfer of genetic material in bacteria F+ and F- factors bacterial biology genetics factors in bacterial genes genetics DNA synthesis mobilization cell to cell contact bridge formation

  • Sé el primero en comentar

Bacterial conjugation

  1. 1. 1
  2. 2. SUBMITTED BY HAFSA ARSHAD ROLL NO: BBOF17M006 Bs.6th Regular SUBMITTED TO: Dr. AMIN ULLAH SHAH DEPARTMENT OF BOTANY UNIVERSITY OF SARGODHA
  3. 3. HISTORY J. Lederberg and E. Tatum demonstrated the transfer of genes between bacteria that depends on – direct cell to cell contact mediated by the F pilus – unidirectional DNA transfer from donor to recipient Bacterial Conjugation
  4. 4. Bacterial Conjugation Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by bridge-like connections between two cells.  The genetic information is often beneficial to the recipient.  Exchange of genetic material b/w bacteria  Physical contact required  DNA exchanged via Pilli  Drug resistance!!  Horizontal Gene Transfer
  5. 5. TERMINOLOGY The Donor F+ Fertility factor Contains genetic material for gene exchange “ Male cell The Recipient F- No fertility factor Receives genetic material Female cell The Conjugate HFR High frequency recombinant Resulting genetic recombinant Transfers entire genomic DNA when mixed with F- cells
  6. 6. Bacterial Plasmids • Small, autonomously replicating DNA molecules – can exist independently from host chromosome – can integrate reversibly into the host chromosome (episomes) • Conjugative plasmids (F plasmid) can transfer copies of themselves to other bacteria during conjugation
  7. 7. 15 • F factors contain the information for formation of sex pilus – attach F+ cell to F- cell for DNA transfer during bacterial conjugation • F factors have insertion sequences (IS) – assists in plasmid integration Bacterial Plasmids - 2
  8. 8. 1- Cell – Cell contact Formation of “sex pilus” or F-bridge between cells Attachment Via Pilli
  9. 9. 2- MOBILIZATION  Target DNA is replicated in F+  Genetic transfer of ssDNA to F- Genetic Transfer of ssDNA
  10. 10. F+ x F- Mating • A copy of the F factor is transferred to the recipient and does not integrate into the host chromosome • Donor genes usually not transferred • F factor codes for sex pilus – Type IV secretion system that makes contact between cells that DNA moves across • Plasmid is replicated by rolling circle method
  11. 11. HFr Conjugation • Donor HFr cell has F factor integrated into its chromosome • Donor genes are transferred to recipient cell • A complete copy of the F factor is usually not transferred • Gene transfer can be clockwise or counterclockwise
  12. 12. 3- DNA SYNTHESIS  Complementary strands of DNA are replicated in both F- and F+  Target DNA is incorporated into F- genome Synthesis of complimentary DNA
  13. 13. 4- SEPARATION  Cells separate  Form two F+ cells with completed recombinant plasmids  Both serve as donor cells for further conjugation Separation and formation of two F+ cells
  14. 14. F’ Conjugation • Result when the F factor incorrectly leaves the host chromosome • Some of the F factor is left behind in the host chromosome • Some host genes have been removed along with some of the F factor – these genes can be transferred to a second host cell by conjugation
  15. 15. Thanks hafsaranjha.botanist@gmail.com

×