Hosting different symbiont species can affect inter‐partner nutritional fluxes within the cnidarian–dinoflagellate symbiosis. Using nanoscale secondary ion mass spectrometry (NanoSIMS), we measured the spatial incorporation of photosynthetically fixed ¹³C and heterotrophically derived ¹⁵N into host and symbiont cells of the model symbiotic cnidarian Aiptasia (Exaiptasia pallida) when colonized with its native symbiont Breviolum minutum or the non‐native Durusdinium trenchii. Breviolum minutum exhibited high photosynthetic carbon assimilation per cell and translocation to host tissue throughout symbiosis establishment, whereas D. trenchii assimilated significantly less carbon, but obtained more host nitrogen. These findings suggest that D. trenchii has less potential to provide photosynthetically fixed carbon to the host despite obtaining considerable amounts of heterotrophically derived nitrogen. These sub‐cellular events help explain previous observations that demonstrate differential effects of D. trenchii compared to B. minutum on the host transcriptome, proteome, metabolome and host growth and asexual reproduction. Together, these differential effects suggest that the non‐native host–symbiont pairing is sub‐optimal with respect to the host's nutritional benefits under normal environmental conditions. This contributes to our understanding of the ways in which metabolic integration impacts the benefits of a symbiotic association, and the potential evolution of novel host–symbiont pairings.

中文翻译：

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亚细胞成像显示非自然内生共生体硬皮杜鹃在模型CNID的过程中减少了光合作用的碳并增加了氮的吸收。

寄养不同共生物种可能会影响猪鞭毛－鞭毛共生中伙伴间的营养通量。使用纳米级二次离子质谱仪（NanoSIMS），我们测定了光合作用固定的¹³ C和异养衍生的¹⁵ N在模型共生触角鞭状盲A（Exaiptasia pallida）的宿主和共生细胞中的空间掺入，其固有的共生种Breviolum minutum或非本地Durusdinium trenchii。灯盏花在每个共生过程中均表现出较高的光合碳同化率，并在每个共生过程中易位到宿主组织。吸收的碳明显减少，但获得了更多的宿主氮。这些发现表明，尽管获得了大量的异养来源的氮，但沟纹果蝇向宿主提供光合固定碳的潜力较小。这些亚细胞事件有助于解释先前的观察结果，这些观察结果显示出与小肠杆状芽胞杆菌相比，海沟D具有不同的作用。宿主转录组，蛋白质组，代谢组以及宿主的生长和无性繁殖。这些差异效应共同表明，就宿主在正常环境条件下的营养益处而言，非本地宿主-共生体配对是次优的。这有助于我们理解代谢整合如何影响共生关联的益处以及新型宿主-共生体配对的潜在进化。