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Sex pheromones and plasmid transfer in Enterococcus faecalis.
1Department of Biologic/Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor 48109.
Plasmid
|May 1, 1989
Summary
Enterococcus faecalis uses sex pheromones to trigger mating responses in plasmid-carrying bacteria. This interaction creates a surface material aiding bacterial aggregation and plasmid transfer.
Area of Science:
- Microbiology
- Molecular Biology
- Bacterial Genetics
Background:
- Enterococcus faecalis utilizes secreted peptides, known as sex pheromones, to mediate conjugation.
- These pheromones specifically interact with recipient bacteria possessing conjugative plasmids, initiating a mating response.
Purpose of the Study:
- To review the biochemistry and genetics of pheromone-mediated conjugation in Enterococcus faecalis.
- To highlight the role of the hemolysin plasmid pAD1 in regulating conjugal transfer.
Main Methods:
- Electron microscopy to visualize surface changes during mating.
- Biochemical and genetic analyses of pheromone production and plasmid regulation.
Main Results:
- Plasmid-free bacteria excrete sex pheromones that induce mating in plasmid-carrying strains.
- A "fuzzy" surface material forms, facilitating donor-recipient aggregation.
- Transconjugants cease endogenous pheromone production but may produce pheromones for other plasmid types.
Conclusions:
- Pheromone-based communication is crucial for Enterococcus faecalis conjugation.
- Plasmid acquisition alters pheromone production, influencing subsequent mating events.
- Regulation of conjugal transfer, exemplified by plasmid pAD1, is complex and involves pheromone interactions.