The impact of environmental change on the ecological and evolutionary dynamics of symbiotic sponge communities.

Lead Research Organisation: University of Aberdeen
Department Name: Inst of Biological and Environmental Sci

Abstract

Microbial communities are present within many hosts, including sponges, which perform a critical ecosystem service, i.e. filtration of seawater. The diversity of the sponge microbiome is related to the sponge species and to the environment in which the sponges live. One of the key waste products of seawater filtration is ammonia and removal of ammonia is facilitated by microbial ammonia oxidisers such as Thaumarchaeota, as they use ammonia as a substrate for their energy generation.
This project aims to understand the ecological and evolutionary mechanisms controlling for the host and niche specialisation and stability (resilience and resistance) of sponge-associated microbes following environmental perturbations influenced by climate change.
- As many organisms are under climate thread, the first aim of this PhD will be to perform a comparative analysis of microbial communities under diverse environmental pressures for determining the effect of climate change on sponge-associated microbes. In addition to general microbial diversity, a particular focus will be on Thaumarchaeota (Gubry-Rangin et al., 2011 and 2015), which are potentially important symbionts.
- Thaumarchaeota contain both free-living and sponge-associated organisms. A second aim of this PhD will be to cultivate sponge-associated Thaumarchaeota, to physiologically characterise these isolates and to compare their genomic content, metabolism and physiology to the collection of free-living Thaumarchaeota available in our laboratory (Lehtovirta-Morley et al., 2016).
- Finally, a diverse set of free-living representative genomes has been recently assembled and used to infer ancestral evolutionary history of this lineage using metagenomic assemblies, phylogenomic reconstruction and associated bioinformatic evolutionary approaches (Sheridan et al., 2020). Following available (and potential additional) sponge sampling in diverse locations (Indonesia, Spain, UK...), the third aim of this PhD will be to analyse the evolutionary lifestyle transition from free-living to symbiotic state in Thaumarchaeota. The student will then assess which genomic pathways have the exciting potential to enable these microbes to respond to several environmental perturbations linked with climate change.
- Based on their interest, there will also be some scope for the student to develop their own line of research.
The student will join an active research group focused on microbial ecology and evolution and more information about the group can be found on our website (https://www.gubry-rangin.com/). The student will also benefit from an interdisciplinary network of collaborators with strong expertise in sponges. Such collaboration will offer some great sampling opportunities and fantastic access to collection databases. Among the diverse approaches applicable to answer these key questions of eco-evo dynamics of symbiotic microbial communities, a combination of novel DNA sequencing and metagenome reconstruction and microbial cultivation would be included. The student will be trained in a series of cutting-edge lab- and computer-based approaches to provide exciting novel discoveries that will contribute to understanding the mechanisms underlying microbial ecology and evolution in natural environments.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
NE/S007342/1 30/09/2019 29/09/2028
2931750 Studentship NE/S007342/1 30/09/2024 30/03/2028 Maeva Mounier