Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Cilia and flagella are tiny-hair-like projections from cells that play important roles in motility and in sensing changes in the cellular environment. Whilst we are familiar with their role in motility, the mechanisms cilia use to sense environmental stimuli and transmit this information to the rest of the cell are less clear. Cilia are built at the tip using a process known as intraflagellar transport (IFT), which enables proteins to be moved along the cilium to the site of assembly. It has also been shown that IFT plays an important role in ciliary signalling, as many important receptor proteins localise to cilia and are moved into and out of the cilium by IFT. Disruption of ciliary signalling due to defects in IFT can lead to human diseases and developmental problems, and it is therefore important for us to understand how intraflagellar transport is regulated. Using the motile green alga, Chlamydomonas, as a model system to study ciliary signalling, we recently discovered that IFT may be regulated by calcium signalling. Many environmental stimuli trigger ion channel proteins in cell membranes to open and cause a rapid influx of calcium ions (Ca2+) into cells. This results in elevated Ca2+ within the cell, which triggers various signalling cascades depending on the nature of the stimulus. Ca2+-dependent signalling processes are central to both the motile and sensory roles of cilia, but we know very little about the nature of these Ca2+ elevations and how they act to regulate ciliary processes. The discovery that Ca2+ signals are regulating IFT therefore links two very important processes in cilia and should help us understand much more about how these organelles sense and respond to their environment. We have used Chlamydomonas to develop a novel microscopy technique that allows us to simultaneously image Ca2+ and the movement of IFT particles in flagella for the first time. Chlamydomonas is currently the only organism in which this technique is possible and this unique ability will allow us to directly examine the mechanisms underlying this novel signalling process. Chlamydomonas can glide along solid substrates on its flagella by using IFT to move proteins in the flagella membrane. Gliding is coordinated by flagella Ca2+ signalling. Ca2+ elevations in one flagellum cause the IFT particles to dissociate from the flagella membrane and stop pulling the cell along. This gliding process is therefore an excellent model system in which to study how Ca2+ signalling regulates IFT to control the movement of flagella membrane proteins. Although we know that Ca2+ regulates IFT, we don't yet know how this happens. This proposal seeks to identify the specific cellular mechanisms responsible. Firstly, we will examine how Ca2+ signals are generated in Chlamydomonas flagella, looking at the ion channels responsible and at mechanisms that restrict Ca2+ elevations to individual flagella, to enable specific control of IFT during the regulation of gliding motility. We will then examine the different types of Ca2+ elevations that are used to regulate IFT, using mathematical models in combination with experimental data to help us understand the rapid changes in Ca2+ concentration inside the flagellum. Finally, we will look at how Ca2+ actually causes the IFT particles to dissociate from the flagella membrane, by identifying specific flagella proteins that may bind to Ca2+ and disrupt this interaction. The process of IFT is highly conserved amongst eukaryotes and it is likely that Ca2+-dependent regulation of IFT influences the movement of many ciliary proteins, including those involved in developmental signalling pathways relating to human genetic diseases. Therefore the results from our studies in algae will provide insight into how ciliary signalling is regulated in many different organisms, including mammals, and shed light on the many different roles cilia play in sensing and responding to the cellular environment.

This NERC highlight topic focuses on the use of eDNA as a new tool for 21st century ecology. Environmental DNA (eDNA) is defined in the call as 'free DNA present outside of any organism'. The aim of the call is to address the current knowledge gaps in the application of eDNA approaches to help understand community biodiversity and dynamics of ecosystem functioning. We will conduct a proof-of-concept investigation at Station L4, an exemplar coastal ocean ecosystem, and natural laboratory, in the English Channel off Plymouth, UK. Starting with a hydrodynamic model to spatially and temporally define the ecosystem (how large is the natural laboratory?) the project will then be split into three experimental phases: 1) eDNA methodological validation (developing the tools); 2) 18-month temporal pelagic survey (testing the tools); and 3) Comprehensive data analysis and model assimilation (did the tools work, what did they tell us, and are they useful?) Using a wide range of expertise from 4 different institutions (PML, MBA, NOC, and U.Exeter), we will investigate a spatially defined region, from estuarine to coastal, benthic to pelagic; and at a range of temporal resolutions building on NERC National Capability sampling regimes and biosensor deployment. E-metagenetic and e-metagenomic data (individual genes to whole genomes) will be used to answer cross-cutting science questions utilising current physicochemical and biological information collected in parallel at this important coastal site. Results from this project will provide a methodological template for the use of eDNA and remote eDNA biosensors in aquatic ecosystems. Downstream data will significantly advance our understanding of persistence of eDNA, and its potential impact on informing models of ecosystem functioning. Products of this research will have wider implications for the use of this tool on fisheries assessments, fish pathogen detection, conservation biology, environmental risk management (e.g. toxic algae blooms, human pathogens, ballast water regulations), with the wider aim of supporting biodiversity and nature's services through NERC's strategic pillar of "Managing environmental change".

Researchers at the Marine Biological Association (MBA) have a long standing reputation for excellence in the use of microscopy to study marine organisms. The ability to observe the unusual and novel physiology of these organisms has led to many significant discoveries. The new microscopy facility requested in this proposal will allow MBA researchers to examine cellular processes at unprecedented levels of resolution, with minimal stress on the cells or organisms under study, providing a world-class facility for future research into cell biology of marine organisms. Research at the MBA relies on advanced fluorescence microscopy techniques to study marine model organisms, using fluorescent dyes and proteins to view where specific proteins are found in a cell or to directly image cellular processes such as changes in intracellular pH or calcium, which are central to many signalling pathways. Other aspects of MBA research use model organisms to study how cellular processes have evolved or may operate in more complex multicellular organisms. For example, we use algae to study the structure and function of flagella, as many aspects of flagella are highly conserved with the cilia found in the human body. Marine phytoplankton are tiny algae that represent the base of the food chain in our oceans, supporting fishing and seafood industries, but despite their importance to life on our planet we still understand very little about them. Many phytoplankton surround themselves with intricate extracellular coverings made from silica or calcium carbonate. We aim to understand how and why these algae produce such intricate and ornate cell coverings to aid the design of similar structures for use in biotechnology and biomedical applications. Other research uses marine organisms from lineages that diverged at the very base of the animal tree of life, such as sea anemones, to examine how complex regulatory processes involved in embryo development evolved in multicellular animals. The marine fungi represent another group of organisms that are poorly understood. Recent research has highlighted that fungi are widespread in marine environments, suggesting that they are likely to play similar roles in nutrient recycling and as pathogens as the terrestrial fungi. We are developing model species of marine fungi for laboratory studies, so that we can understand much more about their physiology and their potential roles in the environment. Fluorescence microscopy of very small cells or structures requires that the subject is illuminated with a bright excitation light, which for many samples can be damaging. This is particularly relevant for photosynthetic organisms (such as marine phytoplankton) or for long term studies (such as time lapse imaging of biomineralisation or embryo development). MBA researchers are therefore currently limited in their ability to study important aspects of their model organisms. This proposal aims to address these limitations through the acquisition of a light sheet microscope. Light sheet microscopes are very effective at reducing damage from excitation light because they illuminate the sample with a very thin layer of light from the side, rather than passing light directly through the sample from above or below. Illumination from the side also has the effect of increasing the resolution of the microscope as there is no interference from out of focus areas of the sample. Light sheet microscopy has been shown to be particularly effective for long term time lapse imaging of photosensitive organisms for extended periods and therefore it is an ideal solution to the problems currently faced by MBA researchers. The new facility will be used to support the ongoing research of the current research teams, with interests from marine fungi and algae through to marine animals, and further afield. The resource will therefore underpin many diverse avenues of research and therefore represents excellent value for money.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.