Department of Biotechnology and Food Science, Faculty of Natural Sciences, Norwegian University of Science and Technology, Trondheim, Norway.
Front Cell Infect Microbiol. 2023 Feb 1;12:1068302. doi: 10.3389/fcimb.2022.1068302. eCollection 2022.
Gnotobiotic models have had a crucial role in studying the effect that commensal microbiota has on the health of their animal hosts. Despite their physiological and ecological diversity, teleost fishes are still underrepresented in gnotobiotic research. Moreover, a better understanding of host-microbe interactions in farmed fish has the potential to contribute to sustainable global food supply. We have developed a novel gnotobiotic experimental system that includes the derivation of fertilized eggs of farmed and wild Atlantic salmon, and gnotobiotic husbandry of fry during the yolk sac stage. We used a microscopy-based approach to estimate the barrier function of the skin mucus layer and used this measurement to select the derivation procedure that minimized adverse effects on the skin mucosa. We also used this method to demonstrate that the mucus barrier was reduced in germ-free fry when compared to fry colonized with two different bacterial communities. This alteration in the mucus barrier was preceded by an increase in the number of cells containing neutral mucosubstances in the anterior segment of the body, but without changes in the number of cells containing acidic substances in any of the other segments studied along the body axis. In addition, we showed how the microbial status of the fry temporarily affected body size and the utilization of internal yolk stores during the yolk sac stage. Finally, we showed that the presence of bacterial communities associated with the fry, as well as their composition, affected the size of adipose tissue. Fry colonized with water from a lake had a larger visceral adipose tissue depot than both conventionally raised and germ-free fry. Together, our results show that this novel gnotobiotic experimental system is a useful tool for the study of host-microbe interactions in this species of aquacultural importance.
无菌动物模型在研究共生微生物对其动物宿主健康的影响方面发挥了关键作用。尽管硬骨鱼类在生理和生态上具有多样性，但在无菌动物研究中它们的代表性仍然不足。此外，更好地了解养殖鱼类中的宿主-微生物相互作用有可能有助于可持续的全球粮食供应。我们开发了一种新的无菌动物实验系统，该系统包括养殖和野生大西洋三文鱼受精卵的衍生，以及在卵黄囊阶段对鱼苗进行无菌饲养。我们使用基于显微镜的方法来估计皮肤黏液层的屏障功能，并使用该测量值来选择衍生程序，以最大程度地减少对皮肤黏膜的不利影响。我们还使用这种方法证明了与定植有两种不同细菌群落的鱼苗相比，无菌鱼苗的黏液屏障减少了。这种黏液屏障的改变先于前体段中含有中性黏蛋白物质的细胞数量增加，但在研究的身体轴上的任何其他段中，含有酸性物质的细胞数量没有变化。此外，我们展示了鱼苗的微生物状态如何在卵黄囊阶段暂时影响身体大小和内部卵黄储备的利用。最后，我们表明与鱼苗相关的细菌群落的存在及其组成会影响脂肪组织的大小。与传统饲养和无菌饲养的鱼苗相比，用湖水饲养的鱼苗的内脏脂肪组织储存更大。总之，我们的研究结果表明，这种新的无菌动物实验系统是研究这种具有水产养殖重要性的鱼类中宿主-微生物相互作用的有用工具。
