BIOSTASIS · BIOlogical SignaTures of AnhydrobioSIS via comparative transcriptomics on different evolutionary lineages within tardigrades
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2018-02-01 → 2020-01-31
- EU contribution
- €200,195
- Participants
- 1
- Scheme
- MSCA-IF
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Results in brief
BIOlogical SignaTures of AnhydrobioSIS via comparative transcriptomics on different evolutionary lineages within tardigrades
The BIOSTASIS project revolved around the study of anhydrobiosis in a tardigrade species ie. Ramazzottius varieornatus. Anhydrobiosis (life without water) is a survival strategy that confers extreme desiccation tolerance. This remarkable phenomenon is present in a limited number of species across the tree of life (animals from four phyla, i.e. Tardigrades, Rotifers, Nematods and Arthropods), selected land plants, certain fungi and bacteria. This strategy is a form of cryptobiosis (latent life), defined by the reversible shut-down of metabolism (biostasis). While desiccated, organisms show no visible signs of life, but they can resume activity in a few minutes to a few hours when placed in a drop of water. Of all the abiotic environmental stressors, desiccation is considered the most detrimental to organisms. Water availability plays a crucial role in defining individual species activity and their ecological interactions, and organisms are frequently confronted with water shortage in both aquatic and terrestrial ecosystems. The most common drivers of dehydration are the evaporative water loss, freezing during winter (and the subsequent reduction of liquid water in extracellular fluids), and hypersalinity. Global environmental change is expected to greatly affect the magnitude of all of these drivers, impacting life at all hierarchical levels, from genes, to species, to ecosystems. Genomic studies on anhydrobionts have led to rapid progress on multiple fronts, yet to date, little is known on the relevance of molecules, genes and mechanisms during the entry and the exit of organisms from anhydrobiosis. Within the BIOSTASIS project, using an experimental set up with several time points, I set the ambitious aim to try and reveal key-player genes involved in the mechanism of anhydrobiosis in a strong cryptobiont tardigrade species ie. Ramazzottius varieornatus. My hypothesis: there could be a potential gene signature for anhydrobiosis, establishing a transcription profile that is characteristic of a given physiological state (active, desiccated or rehydrated) and that could possibly reflect the phylogenetic position of a taxon (ie. organisms that are close relatives could have the same transcription profiles). The project results revealed that the duration of the desiccation stress impacts both the total number of genes that are regulated at the “tun state” and also the recovery time needed for the individuals to return to their normal gene expression levels (as compared to the control samples). The analysed data resulted to new information regarding genes and mechanisms implicated in the mechanisms of anhydrobiosis.
Data: CORDIS, © European Union
Project objective
The current proposal revolves around the dehydration induced state, anhydrobiosis - a survival strategy found among a range of life-forms in face of severe desiccation. Anhydrobiosis is defined by a reversible shut-down of metabolism (biostasis) and it seems to involve adaptations at all levels of organismic organization. The current proposal uses tardigrades as a model to gain novel insight into molecular signatures underlying this unique biological phenomenon. Several molecules have been implicated in the anhydrobiotic mechanism; however, so far studies have been returning contradictory results with respect to the differential expression of genes in pre- and post-anhydrobiotic phases. Interestingly, our preliminary, unpublished data from Møbjerg lab suggest that there could be lineage specific strategies to anhydrobiosis. Consequently, I will use transcriptome sequencing (RNAseq) and ddPCR to reveal key-player genes and characterize functional pathways involved in i) different stages of anhydrobiosis of single tardigrade species and ii) between different evolutionary lineages within the phylum. The mentioned methods constitute the most important training element of my project. The overall goal of the proposal is to determine potential gene expression signatures for anhydrobiosis establishing a transcription profile that is i) characteristic of a particular physiological state and ii) that could possibly reflect the phylogenetic position of a taxon. My previous extensive experience on phylogenetic and molecular dating methods will, in this respect, be utilized to estimate the chronology of the possible diversification of anhydrobiosis within evolutionary lineages. My research will be conducted at the Møbjerg lab, which represents one of the world’s leading groups in the field of tardigrade biology. The group is situated at the Department of Biology, University Copenhagen, which is a superbly equipped institution with a high international profile.
Original text from CORDIS.
Participants
- KOBENHAVNS UNIVERSITET · KOBENHAVNCoordinatorDenmark
Links
Data: CORDIS, © European Union