Piccinni Maya Z, Watts Joy E M, Fourny Marie, Guille Matt, Robson Samuel C
School of Biological Sciences, University of Portsmouth, Portsmouth, UK.
European Xenopus Resource Centre, University of Portsmouth, Portsmouth, UK.
Anim Microbiome. 2021 Feb 5;3(1):17. doi: 10.1186/s42523-021-00080-w.
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.
We found strong evidence for developmental control of the surface microbiome on Xenopus laevis; adults had extremely similar microbial communities independent of their housing, while both tadpole and environmental microbiome communities were less resilient and showed greater diversity.
Our findings suggest that the adult Xenopus laevis microbiome is controlled and selected by the host. This indicates that the surface microbiome of adult Xenopus laevis is stable and defined independently of the environment in which it is housed, suggesting that the use of clean husbandry conditions poses little risk to the skin microbiome when transferring adult frogs to research laboratories. This will have important implications for frog health applicable to Xenopus laevis research centres throughout the world.
从历史上看，实验室非洲爪蟾的主要来源是自然环境。基因改造动物的增加以及政府对使用野生捕获动物进行研究的限制不断演变，促使了资源中心的建立，这些中心在全球范围内供应动物和试剂，比如欧洲非洲爪蟾资源中心。在过去十年中，各中心被鼓励将动物饲养在“低微生物负荷”或“清洁”状态，即胚胎在进入饲养系统前进行表面消毒；而不是采用传统的“标准”条件，即青蛙和胚胎在未经事先表面处理的情况下饲养。尽管非洲爪蟾已被圈养近一个世纪，但令人惊讶的是，对于作为一个共生体的青蛙以及微生物组的变化如何影响疾病抵抗力，人们知之甚少。本研究考察了循环饲养环境中“清洁”和“标准”饲养这两种不同处理条件如何影响蝌蚪和成年雌蛙的皮肤微生物组。当考虑到随着动物从资源中心转移到较小的研究群体，饲养方法的改变可能导致福利变差的可能性时，这一点尤为重要。
我们发现了有力证据，表明非洲爪蟾表面微生物组受到发育控制；成年爪蟾的微生物群落极其相似，与饲养环境无关，而蝌蚪和环境微生物群落的弹性较小且多样性更大。
我们的研究结果表明，成年非洲爪蟾的微生物组由宿主控制和选择。这表明成年非洲爪蟾的表面微生物组是稳定的，且独立于其所处的饲养环境而确定，这意味着在将成年青蛙转移到研究实验室时，采用清洁饲养条件对皮肤微生物组几乎没有风险。这将对全球非洲爪蟾研究中心的青蛙健康产生重要影响。
