Published paper: Metabolomics enables the structure elucidation of a diatom sex pheromone | Marine@Ugent

Published paper: Metabolomics enables the structure elucidation of a diatom sex pheromone


Published paper from Marine@UGent members from the Protistology and Aquatic Ecology group: Metabolomics enables the structure elucidation of a diatom sex pheromone.

 

The work presented solves a major gap in understanding life cycle regulation in the diatoms, the most successful marine eukaryotic phytoplankton group, responsible for ~20% of global primary production. While sexual reproduction in most phytoplankton is induced by environmental cues, diatoms make a remarkable exception because they have a unique life cycle in which cell size is the primary control of sexual capability. We show that mating is under the strict control of size-activated chemical signals that allow the cells to sense the presence and readiness of sexual partners. Based on a novel differential metabolomics approach, we identified L-diproline as the attraction pheromone involved. L-diproline is the first ever identified diatom pheromone and is unprecedented as a pheromone signal. Furthermore, transcriptome analysis revealed that in response to cell size and mating, diatoms employ patched-domain genes that are implicated in cell differentiation in animals.

 

Life cycle regulation in marine phytoplankton is crucial to understanding their ecology and ocean functioning in general. Thousands of different microscopically small algae live in the ocean. They contribute nearly half to the total photosynthesis on earth, but still we do not fully understand how they reproduce. Some of these algae - the diatoms - reproduce mainly by cell division, but since they have a rigid cell wall formed from a ‘biological mineral’ they have to reduce their size during reproduction. Beyond a certain critical size threshold, this process ultimately results in death. They can restore their size by sexual reproduction.

 


Our findings reveal that diatoms can escape this faith by employing a sophisticated, size-controlled mating. Cells sense the presence of mature mating partners and only become sexually active themselves if everything is in place: the time of the day, the cell density and the readiness of the partner. With new analytical techniques we were able to identify the compound that attracts the cells to their mating partners. This work opens new perspectives for a better understanding of the ecological and evolutionary success of diatoms but it also shows ways of how to influence mass cultivation that could potentially be used to generate biofuels and the control of fouling organisms on marine surfaces.

 

Link: http://onlinelibrary.wiley.com/doi/10.1002/anie.201208175/abstract