Contarini P E, Emboule E, Jean-Louis P, Woyke T, Date S V, Gros O, Volland J-M
Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Pointe-à-Pitre, France.
Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States.
Front Microbiol. 2024 Dec 12;15:1491485. doi: 10.3389/fmicb.2024.1491485. eCollection 2024.
Symbiotic interactions drive species evolution, with nutritional symbioses playing vital roles across ecosystems. Chemosynthetic symbioses are globally distributed and ecologically significant, yet the lack of model systems has hindered research progress. The giant ciliate and its sulfur-oxidizing symbionts represent the only known chemosynthetic symbiosis with a short life span that has been transiently cultivated in the laboratory. While it is experimentally tractable and presents a promising model system, it currently lacks an open-source, simple, and standardized cultivation setup. Following the FABricated Ecosystems (EcoFABs) model, we leveraged 3D printing and polydimethylsiloxane (PDMS) casting to develop simple flow-through cultivation chambers that can be produced and adopted by any laboratory. The streamlined manufacturing process reduces production time by 86% and cuts cost by tenfold compared to the previous system. Benchmarking using previously established optimal growth conditions, the new open-source cultivation system proves stable, efficient, more autonomous, and promotes a more prolific growth of the symbiosis. For the first time, starting from single cells, we successfully cultivated the symbiosis in flow-through chambers for 20 days, spanning multiple generations of colonies that remained symbiotic. They were transferred from chamber to chamber enabling long-term cultivation and eliminating the need for continuous field sampling. The chambers, optimized for live imaging, allowed detailed observation of the synchronized growth between the host and symbiont. Highlighting the benefit of this new system, we here describe a new step in the first hours of development where the host pauses growth, expels a coat, before resuming growth, hinting at a putative symbiont selection mechanism early in the colony life cycle. With this simple, open-source, cultivation setup, holds promises for comparative studies, standardization of research and wide adoption by the symbiosis research community.
共生相互作用推动物种进化，营养共生在整个生态系统中发挥着至关重要的作用。化学合成共生在全球范围内分布且具有重要生态意义，但缺乏模型系统阻碍了研究进展。巨型纤毛虫及其硫氧化共生体代表了唯一已知的具有短寿命的化学合成共生关系，且已在实验室中短暂培养。虽然它在实验上易于操作并呈现出一个有前景的模型系统，但目前缺乏开源、简单且标准化的培养设置。遵循人造生态系统（EcoFABs）模型，我们利用3D打印和聚二甲基硅氧烷（PDMS）浇铸技术开发了简单的流通式培养室，任何实验室都可以生产和采用。与之前的系统相比，简化的制造过程将生产时间减少了86%，成本降低了十倍。使用先前确定的最佳生长条件进行基准测试，新的开源培养系统证明是稳定、高效、更自主的，并且促进了共生关系的更丰富生长。首次从单细胞开始，我们成功地在流通式培养室中培养了共生关系20天，跨越了多代仍保持共生的菌落。它们在不同培养室之间转移，实现了长期培养，无需连续进行野外采样。这些培养室针对活体成像进行了优化，能够详细观察宿主与共生体之间的同步生长。为突出这个新系统的优势，我们在此描述了发育最初几个小时的一个新步骤，即宿主暂停生长、排出一层外壳，然后再恢复生长，这暗示了在菌落生命周期早期存在一种假定的共生体选择机制。有了这个简单的开源培养设置，有望开展比较研究、实现研究标准化并被共生研究界广泛采用。
