Multistressor impacts of ocean acidification and warming on regeneration and biomineralisation in coastal sea urchins

The studentship will centre on two inter-connected questions: How will sea urchins remineralise and regenerate their tissues in a future multi-stressor environment? And Are the effects of multiple climate-change associated stressors additive, antagonistic, or synergistic? It will utilise the sea urchin regeneration assay to investigate multiple-climatic stressors using experimental conditions of ocean acidification (OA) and warming (Fig 1). The phenotypic assay has been developed to visualise and quantify spine and tube feet regeneration from a single ambulacral section, by photographing regrowth underwater and analysing the images. In addition to the phenotypic assay, molecular and cellular analyses will be included: targeted gene expression, in-situ hybridisation, and histology on regenerating tube feet and spines, with the potential for complementary transcriptomics and proteomics, representing analyses across levels of biological organisation from genes, cells, and organismal physiology. Comparison experiments with different species will investigate interspecific variation in stressor susceptibility, and species from different latitudinal distributions will provide insight into cold-adapted or warmer-adapted mechanisms. Elemental ratio analysis of calcium carbonate structures will allow characterisation of magnesium content and provide further insights into possible skeletal trade-offs under OA and elevated temperature conditions.