Novel approaches to immortalise salmon fish cells.

动物通常用于生物科学的基础和应用研究。随着养鱼业的发展，人们对疾病如何影响鱼类进行了越来越多的研究，以找到对抗疾病和保护鱼类福利的方法。为了了解病毒如何传播疾病，或者病毒对鱼类的致病性如何，通常会进行实验，即在特殊的封闭水族馆设施中实验感染一群鱼，并监测效果。有时需要用鱼进行实验（体内实验）来回答某些问题，但通常可以通过对永生的鱼细胞进行实验（体外实验）来获得有价值的信息。这些细胞在含有营养物质的合成培养基中在塑料培养皿上无限分裂和生长，并产生细胞系，这是生物材料的无限来源。细胞从最初的几个细胞向外分裂，在培养皿表面形成一层。细胞系通常由一种细胞类型组成，例如肾细胞、心脏细胞或肾细胞。细胞系可用于测试从死鱼中提取的组织样本是否含有病毒（诊断疾病），或者鱼细胞是否可以制造对抗病毒的产品（抗病毒反应）。当病毒被添加到鱼细胞中时，它会感染细胞并杀死它们，这会在细胞层中形成很容易看到的间隙（细胞病变效应）。不幸的是，有许多导致严重疾病的病毒株在目前可用的鱼类细胞系中不能很好地生长。此外，在鱼类中，不可能控制哪种类型的细胞将产生细胞系。这是因为即使你从心脏或肾脏或鳃组织的样本开始，这些组织也是由几种细胞类型组成的，到目前为止，在鱼类中，细胞系是“幸运”产生的，也就是说，组织中的一种细胞类型可能开始分裂并继续分裂，但它可能不是病毒通常感染的细胞类型。事实上，很难将目前可用的一些细胞系分配到特定的鱼类组织中。本项目旨在寻找从目标细胞类型生产鱼类细胞系的新方法。从鱼器官分离的细胞可以被遗传修饰以经历永久的细胞分裂并在合成培养基中存活。这些细胞可以无限繁殖，可以用体外实验代替动物实验。将单独或组合测试几种策略：通过已发现诱导癌细胞分裂和生长的因子，通过生长因子，通过抑制细胞死亡的因子，通过已知触发血细胞增殖的寄生虫产生的因子使细胞永生化。可以产生这些因子的遗传系统将被引入从不同组织类型分离的初始细胞中，并且这些因子将作用于细胞以保持其分裂和/或防止其死亡。最终目的是减少调查和诊断鱼病所需的活鱼数量，并提供用于改善鱼类健康和福利的工具。随着野生鱼类种群面临的压力越来越大，世界人口不断增加，水产养殖已成为许多社区蛋白质的重要供应者，而且很可能继续增长。

Animals are commonly used in biological sciences for both fundamental and applied research. With the growth of the fish farming industry, more and more studies are carried out to understand how disease affects fish in order to find ways to combat them and protect fish welfare.To gain understanding on how a virus can transmit disease, or how pathogenic it is for the fish experiments are often carried out where a group of fish is experimentally infected in a special containment aquarium facility and the effects monitored. It is sometimes necessary to carry out experiments with fish (in vivo experiments) to answer certain questions but often valuable information can be obtained by performing the experiments instead on immortal fish cells (in vitro experiments). These are cells which divide and grow indefinitely on plastic dishes in a synthetic culture medium containing nutrients and give rise to a cell line, an indefinite source of biological material. The cells divide outwards from a few initial cells to form a layer on the surface of the dish. The cell lines are usually composed on one cell type, e.g. a kidney cell, heart cell or kidney cell. Cell lines can be used to test whether a tissue sample taken from a dead fish contains a virus or not (diagnosing disease), or whether the fish cell can make products to combat the virus (anti-viral response). When the virus is added to the fish cells, it infects the cells and kills them and this forms gaps in the cell layer which are easily seen (cytopathic effect). Unfortunately, there are many strains of viruses responsible for serious diseases that do not grow very well in the fish cell lines currently available. In addition in fish there is no possibility to control what type of cell will generate a cell line. This is because even if you start with a sample of heart or kidney or gill tissue, these tissues are made up of several cell types and to date, in fish, cell lines are generated "by luck", that is, one of the cell types in the tissue may start to divide and continue to do so, but it may not be the cell type which the virus normally infects. In fact, it is difficult to allocate some of the currently available cell lines to a certain fish tissue.The present project aims to find new methods to produce fish cell lines from targeted cell types. Cells dissociated from fish organs can be genetically modified to undergo a permanent cell division and survive in synthetic culture medium. These cells would propagate indefinitely and can be used to replace animal experiments by in vitro ones. Several strategies will be tested alone or in combination: immortalisation of cells by factors which have been found to induce cancer cells to divide and grow, by growth factor, by factors which inhibit cell death, by factors produced by parasites known to trigger the proliferation of blood cells. Genetic systems which can produce these factors will be introduced into the initial cells isolated from different tissue types, and the factors will act on the cell to keep it dividing and/or prevent it from dying. The ultimate aim is to reduce the number of live fish needed to investigate and diagnose fish disease and to provide tools for use in improving fish health and welfare. With increasing pressure on wild fish stocks and an increasing world population, aquaculture has become an important provider of protein for many communities and will most likely continue to grow.