Candida albicans produces farnesol as an extracellular quorum-sensing molecule. After accumulation above a threshold level, farnesol prevents the yeast to mycelium transition and also blocks formation of biofilm. To our surprise, at concentrations ranging from 20 mM and 200 mM, farnesol has no apparent effect on hyphal morphogenesis in Aspergillus nidulans. Instead, it triggered rapid DNA condensation independent of mitosis, intense DNA fragmentation and exposure of phosphatidylserine. These are morphological features that are characteristic of apoptosis. Moreover, farnesol treatment also induced the accumulation of reactive oxygen species. Farnesol is not produced by A. nidulans hyphae during growth in liquid culture media, suggesting that it is not acting as a quorum-sensing molecule to regulate colony morphology. Instead, we propose that A. nidulans responds to farnesol produced by other fungal species. Future efforts will address the mechanism of farnesol-induced apoptosis, with the goal of identifying potentially novel targets for the development of anti-fungal compounds.
Full conference title:
23rd Fungal Genetics Conference
- Fungal Genetics Conference 23rd (2002)