The skin microbiome of Xenopus laevis and the effects of husbandry conditions. Xenopus laevis skin metagenome

Historically the main source of laboratory Xenopus laevis was the environment. The increase in genetically altered animals and evolving governmental constraints around using wild-caught animals for research has led to the establishment of resource centres that supply animals and reagents worldwide, such as the European Xenopus Resource Centre. In the last decade, centres were encouraged to keep animals in a 'low microbial load' or 'clean' state, where embryos are surface sterilized before entering the housing system; instead of the conventional, 'standard' conditions where frogs and embryos are kept without prior surface treatment. Despite Xenopus laevis having been kept in captivity for almost a century, surprisingly little is known about the frogs as a holobiont and how changing the microbiome may affect resistance to disease. This study examines how the different treatment conditions, 'clean' and 'standard' husbandry in recirculating housing, affects the skin microbiome of tadpoles and female adults. This is particularly important when considering the potential for poor welfare caused by a change in husbandry method as animals move from resource centres to smaller research colonies.

历史上，实验室用非洲爪蟾（Xenopus laevis）的主要来源为野生环境。随着基因改造动物的数量持续增长，以及各国针对科研用野生捕获动物的监管约束日趋严格，全球范围内陆续建立了供应实验动物与相关试剂的资源中心，例如欧洲非洲爪蟾资源中心（European Xenopus Resource Centre）。近十年来，相关机构被倡导将实验动物饲养于"低微生物负荷"或"洁净"环境中：即胚胎在进入饲养系统前需完成表面灭菌处理，而非传统的"标准"饲养模式——即蛙类与胚胎无需预先进行表面处理即可直接饲养。尽管非洲爪蟾已被人工饲养近百年，但学界对其作为全共生体（holobiont）的生物学特性，以及微生物组改变如何影响其抗病能力的认知仍十分有限。本研究旨在探究循环饲养系统中，"洁净"与"标准"两种不同饲养管理条件对蝌蚪以及成年雌性非洲爪蟾皮肤微生物组的影响。当实验动物从资源中心转移至小型科研养殖种群时，饲养方式的改变可能会对动物福利造成不良影响，因此该研究主题具有重要的现实意义。