Chung Sheena Suet-Wah, Cheung Khan, Arromrak Bovern Suchart, Li Zhenzhen, Tse Cham Man, Gaitán-Espitia Juan Diego
The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China.
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
Environ Microbiome. 2024 Oct 13;19(1):74. doi: 10.1186/s40793-024-00620-2.
Environmental gradients can influence morpho-physiological and life-history differences in natural populations. It is unclear, however, to what extent such gradients can also modulate phenotypic differences in other organismal characteristics such as the structure and function of host-associated microbial communities. In this work, we addressed this question by assessing intra-specific variation in the diversity, structure and function of environmental-associated (sediment and water) and animal-associated (skin and gut) microbiota along an environmental gradient of pollution in one of the most urbanized coastal areas in the world. Using the tropical sea cucumber Holothuria leucospilota, we tested the interplay between deterministic (e.g., environmental/host filtering) and stochastic (e.g., random microbial dispersal) processes underpinning host-microbiome interactions and microbial assemblages. Overall, our results indicate that microbial communities are complex and vary in structure and function between the environment and the animal hosts. However, these differences are modulated by the level of pollution across the gradient with marked clines in alpha and beta diversity. Yet, such clines and overall differences showed opposite directions when comparing environmental- and animal-associated microbial communities. In the sea cucumbers, intrinsic characteristics (e.g., body compartments, biochemistry composition, immune systems), may underpin the observed intra-individual differences in the associated microbiomes, and their divergence from the environmental source. Such regulation favours specific microbial functional pathways that may play an important role in the survival and physiology of the animal host, particularly in high polluted areas. These findings suggest that the interplay between both, environmental and host filtering underpins microbial community assembly in H. leucospilota along the pollution gradient in Hong Kong.
环境梯度可以影响自然种群的形态生理和生活史差异。然而，尚不清楚这种梯度在多大程度上还能调节其他生物特征的表型差异，比如宿主相关微生物群落的结构和功能。在这项研究中，我们通过评估世界上城市化程度最高的沿海地区之一沿污染环境梯度的环境相关（沉积物和水）及动物相关（皮肤和肠道）微生物群落在多样性、结构和功能上的种内变异，来解决这个问题。我们以热带海参白底辐肛参为研究对象，测试了决定论（如环境/宿主筛选）和随机过程（如随机微生物扩散）之间的相互作用，这些过程是宿主-微生物组相互作用和微生物群落形成的基础。总体而言，我们的结果表明，微生物群落是复杂的，其在环境和动物宿主之间的结构和功能存在差异。然而，这些差异受到整个梯度污染水平的调节，α和β多样性呈现明显的梯度变化。然而，在比较环境相关和动物相关微生物群落时，这种梯度变化和总体差异呈现相反的方向。在海参中，内在特征（如身体部位、生化组成、免疫系统）可能是观察到的相关微生物组个体内差异及其与环境来源差异的基础。这种调节有利于特定的微生物功能途径，这些途径可能在动物宿主的生存和生理过程中发挥重要作用，尤其是在高污染地区。这些发现表明，环境筛选和宿主筛选之间的相互作用是香港沿污染梯度的白底辐肛参微生物群落组装的基础。
