Conjugation

CONJUGATION
  • In conjugation, transfer of DNA occurs between a mating pair of cells followed by separation of the cells.
  • In this process large fragments of DNA can be transferred. In E.coli the donor (male) cells contain a small circular piece of DNA which is extrachromosomal. It is called the sex factor or fertility (F) factor.
  • These cells are referred as F+. The recipient (female) cells lack this factor and are referred as F-. Sex pili bind to the F- cell and retract it into F+ cell. They also act as tubules through which DNA passes from F+ cell to F- cell. Transfer of DNA can also occur at sites of contact between the cells.
  • The donor cell replicates its sex factor and one copy of it is transferred to the recipient.
  • Now the F- cell is converted it into F+ cell and can act as a donor cell.

Illustration for conjugation

Last modified: Saturday, 12 May 2012, 10:19 AM