A new aquarium for the UCL Fish Facility

The structures, forms and functions of the vertebrate body are largely established during the early stages of development and involve processes that are remarkably similar throughout the different vertebrate groups, from fish to mammals. Advances in molecular genetics have led to a dramatic expansion in our knowledge of how these fundamental developmental processes work and how conserved they are between vertebrate species. This expansion in our knowledge has been achieved largely by studying a limited number of model vertebrate organisms. The zebrafish is now one of the most widely used model systems in part because of its genetic tractability - the ability to define gene functions through genetic approaches including screens. In performing what is called a "forward genetic screen", mutations are randomly induced in genes throughout the genome and then screens identify which of these mutations affect the developmental process under study. This approach gives a relatively unbiased way to find the genes required for specific developmental processes. An alternative "reverse genetic" approach is to "knock-out" the activity of genes that might be involved in the process of interest, and relies on some prior notion of the likely function of the gene. Both 'forward' and 'reverse' genetic approaches are feasible in fish and are being used to study many aspects of development, organ function and neurobiology. Another major advantage of zebrafish is its optical transparency allowing investigations into cell movements, developing neuronal connections, as well as tracking neuronal activity in response to perceived stimuli in the living animal with no or only minimal intervention.

This grant provides funds a new state of the art aquarium to maintain many distinct lines of fish used by many researchers at UCL and beyond. The new aquarium will enable fish to be maintained in an isolated, disease-free environment ensuring optimal rearing conditions, health and breeding performance from the adult fish.

The new aquarium will support a wide range of research and animal welfare projects that use zebrafish as a model system. Several of the research teams that will use the aquarium study the processes by which the nervous system forms. Research ranges from study of the developmental mechanisms by which neurons are generated, acquire their identities and form connections to investigation of the resulting neural circuits that mediate behaviours. For instance, researchers are examining the neural networks underlying circadian rhythms and sleep, as well as visually guided behaviours such as hunting. Maybe surprisingly, even very young zebrafish fry exhibits social preference and so we can study this type of social behaviour. Advances in molecular, imaging and computational approaches allow us to study the neural basis of behavioural responses at cellular resolution and identify the specific neurons that are involved in receiving sensory information and those involved in eliciting behavioural responses. Other research teams are studying aspects of cell biology in living fish embryos including addressing how epithelia are formed and function and how cells behave as they migrate within the embryo. Many of the projects will be supported by the use of the genetic screens described above that help us to identify the key genes involved in the processes under study. We will also develop methods and approaches that help to reduce and refine the use of animals in research. For instance we aim to determine the gene defects carried by individual fish when they are embryos so that we only grow those fish we specifically need for experiments. We will also aim to improve animal husbandry and care procedures and assess how rearing conditions affect subsequent behaviours of the young fish.

This application seeks funds to install a new state of the art, specific pathogen free aquarium with tank washing and autoclaving capability within the UCL Fish Facility. The aquarium will support a wide range of research and animal welfare projects that use zebrafish as a model system. The aquarium will provide the space needed for both forward and reverse genetic screening projects. For instance, Crispr/Cas9 based abrogation of gene function will complement and inform analysis of mutants from phenotype based screens through, for instance, facilitating analysis of genetic interactions. Much of the genetic screening aims to identify genes required for morphogenesis of the CNS, neurogenesis, acquisition of neuronal identity circuit formation and behaviour. Researchers are examining the neural networks underlying circadian rhythms and sleep, visually guided behaviours such as hunting and social behaviours, such as social preference. Other research teams are studying aspects of cell biology in living fish embryos including addressing how epithelia are formed and how cell migration is regulated in vivo. The aquarium will also support the development of methods and approaches that help to reduce and refine the use of animals. For instance we aim to establish methods to genotype embryos such that only those carrying alleles of interest are raised to adulthood. We also aim to develop protocols to improve animal husbandry and care procedures, including studies addressing nutrition, anaesthesia, health monitoring, spawning and reproductive studies. The aquarium also will support training and outreach activities including Royal Society of Biology accredited courses for research and technical personnel and hosting events for the public, students and teachers.

UCL's zebrafish research community encompasses a diverse group of scientists asking a wide range of questions using techniques from in vivo cell biology to largescale developmental and behavioural screens, and increasingly, data driven approaches facilitated by recent advances in imaging and data processing. Due to its genetic tractability, small size and optical transparency, the zebrafish is at the forefront of technological innovation in the Biosciences. Thus, with the new aquarium, the Facility will not only be able to fully support all currently ongoing research activity, but will enable ambitious new research projects using the zebrafish model.

One novel project that will be enabled by the new aquarium will be the establishment of a platform for molecular, neuroanatomical, functional and behavioural phenotyping of wildtype and genetically altered fish. Between the Wilson, Rihel, Bianco, Hawkins and Dreosti labs, we consider that we have world-leading expertise in identifying nervous system phenotypes in zebrafish and have started to use our combined expertise to generate innovative new screening approaches, for example for mutation identification and for automated, high-throughput behaviour phenotyping. Research will also use pioneering in vivo imaging approaches to address aspects of fundamental cell biology such are the molecular regulation of cell division, tissue polarisation and cell migration. We expect that the results of the research that comes from our screens and research programmes will lead to further discoveries that, ultimately, will not only expand our understanding of basic biological processes but also impact on human health and disease by facilitating new approaches to understanding the events that when perturbed can lead to disease and by promoting drug-discovery that has the potential to benefit society as a whole.

The aquarium will also enable generation of many novel lines of fish carrying mutations and/or transgenes; these lines will be made freely available to the international research community, increasing research capacity and productivity. Similarly new methods that will be developed will be widely disseminated and have the potential to increase research efficiency and broaden the scope of research projects.

In addition to providing essential support to researchers at UCL and beyond, the aquarium will facilitate research and adoption of practices relevant to the application of the 3Rs and to best practice for animal welfare. The "Special Pathogen Free' (SPF) status of the aquarium will enable projects to assess the effect of low pathogen load on fecundity and reproducibility of research findings and on animal welfare in general. The aquarium will allow us to raise and maintain animals for research under the best welfare conditions (Refinement). The health monitoring and improved health status of the fish will affect fecundity, thus we expect to maintain fewer fish to obtain the numbers of offspring required for our research (Reduction). To disseminate the outcome of such activities and research, the Facility will continue to publish papers and present their research to academic and fish technology audiences building on past successes with poster awards and other prizes. As in the past, we expect procedures developed within the Facility to be used as a reference guide for best practice standards with respect to fish rearing, welfare and maintenance

The UCL Fish Facility has widely been considered exemplary and one of the most technologically advanced facility of its kind serving an academic community. The new aquarium is vital to maintain the effectiveness and output of the Facility that underlies its success and reputation.

We do not anticipate any major discoveries during the 12 month tenure of the grant. However, the equipment will continue to serve the applicants, other UCL researchers and the wider scientific community for at least 10 years to 15 years.