Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA.
mSphere. 2018 Mar 28;3(2). doi: 10.1128/mSphere.00531-17. eCollection 2018 Mar-Apr.
Female Hawaiian bobtail squid, Euprymna scolopes, harbor a symbiotic bacterial community in a reproductive organ, the accessory nidamental gland (ANG). This community is known to be stable over several generations of wild-caught bobtail squid but has, to date, been examined for only one population in Maunalua Bay, Oahu, HI. This study assessed the ANG and corresponding egg jelly coat (JC) bacterial communities for another genetically isolated host population from Kaneohe Bay, Oahu, HI, using 16S amplicon sequencing. The bacterial communities from the ANGs and JCs of the two populations were found to be similar in richness, evenness, phylogenetic diversity, and overall community composition. However, the Kaneohe Bay samples formed their own subset within the Maunalua Bay ANG/JC community. An genus, BD2-13, was significantly higher in relative abundance in the Kaneohe Bay population, and several taxa also shifted in relative abundance between the two groups. This variation could be due to local adaptation to differing environmental challenges, to localized variability, or to functional redundancy among the ANG taxa. The overall stability of the community between the populations further supports a crucial functional role that has been hypothesized for this symbiosis. In this study, we examined the reproductive ANG symbiosis found in two genetically isolated populations of the Hawaiian bobtail squid, Euprymna scolopes. The stability of the community reported here provides support for the hypothesis that this symbiosis is under strong selective pressure, while the observed differences suggest that some level of local adaptation may have occurred. These two host populations are frequently used interchangeably as source populations for research. Euprymna scolopes is an important model organism and offers the opportunity to examine the interplay between a binary and a consortial symbiosis in a single model host. Understanding the inherent natural variability of this association will aid in our understanding of the conservation, function, transmission, and development of the ANG symbiosis.
夏威夷短尾乌贼的雌性个体在其生殖器官附属缠卵腺（ANG）中携带有一个共生细菌群落。这个共生细菌群落已经被证实可以在几代野生短尾乌贼中保持稳定，但迄今为止，仅在夏威夷瓦胡岛的毛纳罗亚湾对一个种群进行了研究。本研究使用 16S 扩增子测序技术，对来自瓦胡岛卡内奥赫湾的另一个遗传隔离宿主种群的 ANG 和相应的卵果冻层（JC）细菌群落进行了评估。结果发现，两个种群的 ANG 和 JC 中的细菌群落在丰富度、均匀度、系统发育多样性和整体群落组成方面相似。然而，卡内奥赫湾样本在毛纳罗亚湾 ANG/JC 群落中形成了自己的子集。属 BD2-13 的相对丰度在卡内奥赫湾种群中显著较高，并且两组之间的几个 分类群的相对丰度也发生了变化。这种变化可能是由于对不同环境挑战的局部适应、局部变异性或 ANG 分类群之间的功能冗余。两个种群之间群落的总体稳定性进一步支持了这种共生关系所假设的关键功能作用。在这项研究中，我们检查了夏威夷短尾乌贼的两个遗传隔离种群中发现的生殖 ANG 共生关系。这里报告的群落稳定性为这样一种假设提供了支持，即这种共生关系受到强烈的选择性压力，而观察到的差异表明可能发生了某种程度的局部适应。这两个宿主种群经常被互换用作研究的来源种群。夏威夷短尾乌贼是一种重要的模式生物，它提供了一个机会，可以在单个模型宿主中研究二元共生和共生关系之间的相互作用。了解这种关联的固有自然变异性将有助于我们理解 ANG 共生关系的保护、功能、传播和发育。
