Reducing the use and refining the distribution of male Xenopus

为了了解人类和动物的正常生物过程，以及当这些过程出错时发生的疾病，我们需要研究“模式生物”。除了在伦理上更可取之外，使用模型进行研究的历史也很长，因此我们既有大量关于它们的信息，又有广泛的实验工具可供使用。四种主要的脊椎动物模式生物中有两种是来自非洲的水生爪蟾蛙。我们对基础动物生物学的大部分知识都来自使用非洲爪蟾的研究，包括：细胞分裂控制，细胞间信号传导，细胞重编程，再生和愈合，基因控制网络和DNA修复。最近，它们被用于研究人类遗传疾病，超过90%的人类基因在非洲爪蟾中被发现，超过三分之二的基因组结构是相同的，为了支持使用模式生物，资源中心制作，收集，质量保证和分配所需的所有分子和动物资源。对非洲爪蟾来说，主要的资源中心是EXRC，它与美国和日本的中心密切合作，以确保满足全世界研究人员的需求。EXRC的部分使命是改善用于研究的青蛙的福利，该项目有助于实现这一目标。目前，雄性青蛙被送到研究实验室，在那里它们被保存在水箱中，然后，当需要用于实验的胚胎时，它们被人道地杀死，并将其睾丸取出，以提供体外受精的精子。这有两个缺点，我们的目标是克服：第一，青蛙在旅行中受到压力，第二，因为一次受精产生了如此多的胚胎（通常超过实验中可以分析的数量），在所有精子被使用之前，被移除的睾丸通常会变得不活跃，导致浪费。与我们的合作者和美国库存中心一起，我们开发了冷冻精子的强大方法，最近成功地进行了三次将男性配子作为冷冻精子发送给国外研究人员的试验。我们现在需要发展这一过程，使其能够广泛使用。要做到这一点，我们将首先测试我们是否可以将每个男性的睾丸分成超过我们目前使用的8个部分，而不影响受精率和所产生胚胎的发育命运。然后，我们将评估每一块睾丸产生胚胎的变异性，使我们能够了解如何最好地保证我们发送给用户的精子的质量。该计划的下一阶段是开发分销流程，首先是通过向全球7个实验室发送虚拟包裹来测试不同快递公司的服务，并优化包装和文书工作，以加快通过海关的速度。一旦我们确定了交付过程，我们将发送冷冻精子，并通过Skype讨论在测试实验室中使用这些精子。我们将利用这些讨论来改进随精子发送的更多批次的书面和视频说明。一旦我们持续地向测试实验室分发冷冻精子，我们将把服务扩展到所有需要的用户，并鼓励其他储备中心也这样做。我们相信，用户将接受这项服务，因为它代表了大量的成本节省比发送活动物。该计划将提供一个更符合成本效益的方式发送雄性非洲爪蟾配子，同时提高动物福利和减少使用的雄性青蛙的数量。

To understand the normal biological processes in humans and animals, together with the diseases that occur when these go wrong, we need to study "model organisms". In addition to being ethically preferable, there is a long history of research using the models, so we have both a great deal of information about them and a wide range of experimental tools to work with. Two of the four main vertebrate model organisms are aquatic Xenopus frogs that come from Africa. Much of our knowledge about basic animal biology comes from research using Xenopus, including: cell division control, intercellular signaling, cell reprogramming, regeneration and healing, gene control networks and DNA repair. More recently they have been used to study human genetic diseases, more than 90% of human genes are found in Xenopus and the structure of over two-thirds of their genomes is the same.To support the use of model organisms, resource centres make, collect, quality assure and distribute all of the molecular and animal resources needed. For Xenopus the main resource centre is the EXRC, which collaborates closely with centres in the US and Japan to ensure that researchers' needs are met worldwide. Part of the EXRC's mission is to improve the welfare of frogs used for research and this project contributes to that aim. Currently male frogs are sent to research laboratories where they are kept in tanks and then, when embryos for experiments are needed, they are killed humanely and their testes removed to provide the sperm for in vitro fertilization. This has two disadvantages we aim to overcome: first the frogs are stressed by travel and second, because so many embryos are created by one fertilization (often more than can be analysed in an experiment) the removed testes often become inactive before all of the sperm are used, leading to wastage. Together with our collaborators and the US stock centre we have developed robust methods for freezing sperm and recently performed three successful trials of sending male gametes as frozen sperm to researchers based abroad. We now need to develop this process to the point where it can be widely used. To do so we will first test whether we can divide the testes from each male into more than the 8 sections that we currently use, without affecting fertilization rates and the developmental fate of the embryos produced. We will then assess the variability of embryo production from each piece of testis, allowing us to understand how best to quality assure the sperm we send to our users. The next stage of the programme is to develop the distribution process, first by testing different courier's services using dummy packages to a group of 7 labs around the world and optimizing the packaging and paperwork to speed passage through customs. Once we are sure of the delivery process, we will send frozen sperm and discuss the use of these in the test laboratories by Skype. We will use these discussions to improve the written and video instructions that accompany the sperm as more batches are sent out. Once we are consistently distributing frozen sperm to the test laboratories we will then extend the service to all of our users who want it and encourage the other stock centres to do so too. We are confident that users will take up this service due to the substantial cost savings it represents over sending live animals.This programme will deliver a more cost effective way of sending male Xenopus gametes whilst improving animal welfare and decreasing the number of male frogs used.