Reef-building corals form associations with a huge diversity of microorganisms, which are essential for the survival and well-being of their host. While the acquisition patterns of Symbiodiniaceae microalgal endosymbionts are strongly linked to the coral's reproductive strategy, few studies have investigated the transmission mode of bacteria, especially in brooding species. Here, we relied on 16S rRNA gene and Internal Transcribed Spacer 2 marker metabarcoding in conjunction with fluorescence in situ hybridisation microscopy to describe the onset of microbial associations in the common brooding coral Pocillopora acuta. We analysed the bacterial and Symbiodiniaceae community composition in five adult colonies, their larvae, and 4-day old recruits. Larvae and recruits inherited Symbiodiniaceae, as well as a small number of bacterial strains, from their parents. Rhodobacteraceae and Endozoicomonas were among the most abundant taxa that were likely maternally transmitted to the offspring. The presence of bacterial aggregates in newly released larvae was observed with confocal microscopy, confirming the occurrence of vertical transmission of bacteria in P. acuta. We concluded that host factors, as well as the environmental bacterial pool influenced the microbiome of P. acuta.

中文翻译：

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常见的育雏珊瑚 Pocillopora acuta 中的混合模式细菌传播。

造礁珊瑚与种类繁多的微生物形成关联，这些微生物对于宿主的生存和福祉至关重要。虽然共生藻科微藻内共生体的获取模式与珊瑚的繁殖策略密切相关，但很少有研究调查细菌的传播模式，尤其是育雏物种。在这里，我们依靠 16S rRNA 基因和 Internal Transcribed Spacer 2 标记元条形码结合荧光原位杂交显微镜来描述普通育雏珊瑚 Pocillopora acuta 中微生物关联的开始。我们分析了五个成虫群落、它们的幼虫和 4 日龄新兵的细菌和共生藻科群落组成。幼虫和新兵继承了共生藻科，以及少量细菌菌株，来自他们的父母。Rhodobacteraceae 和 Endozoicomonas 是最丰富的类群之一，可能通过母系传播给后代。用共聚焦显微镜观察到新释放的幼虫中细菌聚集体的存在，证实了尖形假单胞菌中细菌垂直传播的发生。我们得出结论，宿主因素以及环境细菌库影响了尖吻棘假单胞菌的微生​​物组。