Hyams Yosef, Rubin-Blum Maxim, Rosner Amalia, Brodsky Leonid, Rinkevich Yuval, Rinkevich Baruch
Israel Oceanographic and Limnological Research, National Institute of Oceanography, Haifa, Israel.
Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel.
Front Microbiol. 2023 May 31;14:1072053. doi: 10.3389/fmicb.2023.1072053. eCollection 2023.
Environmental perturbations evoke down-regulation of metabolism in some multicellular organisms, leading to dormancy, or torpor. Colonies of the urochordate enter torpor in response to changes in seawater temperature and may survive for months as small vasculature remnants that lack feeding and reproductive organs but possess torpor-specific microbiota. Upon returning to milder conditions, the colonies rapidly restore their original morphology, cytology and functionality while harboring re-occurring microbiota, a phenomenon that has not been described in detail to date. Here we investigated the stability of microbiome and its functionality in active and dormant colonies, using microscopy, qPCR, hybridization, genomics and transcriptomics. A novel lineage of , proposed here as Endozoicomonas endoleachii, was dominant in torpor animals (53-79% read abundance), and potentially occupied specific hemocytes found only in torpid animals. Functional analysis of the metagenome-assembled genome and genome-targeted transcriptomics revealed that can use various cellular substrates, like amino acids and sugars, potentially producing biotin and thiamine, but also expressing various features involved in autocatalytic symbiosis. Our study suggests that the microbiome can be linked to the metabolic and physiological states of the host, , introducing a model organism for the study of symbioses during drastic physiological changes, such as torpor.
环境扰动会导致一些多细胞生物的新陈代谢下调，从而进入休眠或蛰伏状态。尾索动物群体在海水温度变化时会进入蛰伏状态，作为缺乏摄食和生殖器官但拥有特定蛰伏微生物群的小型脉管系统残余物，它们可能存活数月。回到较温和的条件下后，这些群体迅速恢复其原始形态、细胞学和功能，同时保留反复出现的微生物群，这一现象迄今为止尚未得到详细描述。在这里，我们使用显微镜、定量聚合酶链反应、杂交、基因组学和转录组学方法，研究了活跃和休眠群体中微生物组的稳定性及其功能。一种新的 谱系，这里命名为内栖嗜菌内栖单胞菌（Endozoicomonas endoleachii），在蛰伏动物中占主导地位（读取丰度为53%-79%），并且可能占据仅在蛰伏动物中发现的特定血细胞。对宏基因组组装基因组和基因组靶向转录组学的功能分析表明， 可以利用各种细胞底物，如氨基酸和糖类，可能产生生物素和硫胺素，同时还表达参与自催化共生的各种特征。我们的研究表明，微生物组可能与宿主的代谢和生理状态相关， 引入了一种模式生物，用于研究诸如蛰伏等剧烈生理变化期间的共生现象。
