© C. Bowler & K. Osada Electron microscopy of diatom silica shells.
© C. Bowler & K. Osada
Electron microscopy of diatom silica shells.
Diatoms undergo seasonal population explosions, known as phytoplankton blooms. These blooms attract billions of predators, from which diatoms protect themselves by releasing aldehyde compounds. However, these chemicals not only compromise the hatching success of grazers, they also kill the diatoms themselves. Interestingly, diatoms have a sophisticated calcium and nitric oxide-based surveillance system for monitoring environmental stresses that can detect the release of aldehydes by its wounded neighbours. Bowler and his colleagues show that the response to aldehyde is dose-dependent–high doses of aldehyde trigger cell death, which may lead to the termination of a bloom. However, low doses induce resistance to the compound's toxic effect. Diatoms thus adapt cell fate by actively monitoring their environment. Bowler's work suggests that they communicate among themselves and sometimes commit mass suicide.
Bowler is keen to explore other aspects of diatom communication. For example, diatom afficionados have long known that the organisms have sex. However, exactly how they do it and how they find each other in the water is still unknown. Perhaps diatoms are doing a lot more communicating than we think.
1. Vardi A et al., “A stress surveillance system based on calcium and nitric oxide in marine diatoms.” PLoS Biol. 4 (3): e60. 2006.
2. Laboratoire Signalisation et morphogenèse des diatomées (CNRS / Ecole Normale Supérieure joint lab).
Ecole Normale supérieure, Paris.