Uncovering the Defensome genetic toolkit of marine embryos in the context of climate change

Intensification of the frequency and severity of harmful algae blooms (HABs) has recently increased due to climate change and global warming, affecting environment, human health as well as local economies based on fishing and/or recreational activities.

Some diatom species (representing half of the primary production of the oceans) synthesize biotoxic compounds derived from secondary metabolites known as oxylipins, which are highly produced during HABs upon cell damage.

Several studies have reported that Polyunsaturated aldehydes (PUAs), among the most studied oxylipins, have negative effects on many marine organisms, reporting impairment of growth, reproduction, cell homeostasis and detoxification. However, the genetic mechanisms that regulate these physiological responses are still unknown.

It has been proposed that some organisms could have a set of conserved genes that will be activated upon PUAs exposure, the so call ‘Defensome’, but few members had been described. The larvacean Oikopleura dioica is one of the many organisms affected by PUAs.

In addition of being among the most abundant components of the mesozooplankton, O. dioica is an “evolutionary-knockout” for many signalling pathways being a perfect candidate to study biological adaptations by gene loss.Using O. dioica as animal model we aim to identify conserved Defensome genes shared among marine animals and to study the developmental pathways affected by biotoxins.

To achieve this goal, we will combine transcriptomics (RNASeq), chromatin accessibility (ATAC-Seq) and gene interference approaches (RNAi, DNAi, Cas9-CRISPR).

The results of this project will be key for understanding the genetic adaptive response of marine embryos to the biotoxic impact of HABs on marine environments worldwide.

Moreover, the discovery of a conserved set of Defensome genes across different groups of marine animals, could provide a useful set of pan-markers of environmental stress for be applied in many different species.