Applied Biosciences, Macquarie University, North Ryde, NSW 2113, Australia.
School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia.
Int J Mol Sci. 2022 Apr 28;23(9):4913. doi: 10.3390/ijms23094913.
Heat-tolerant strains of the coral endosymbiont, C1 (Symbiodiniaceae), have previously been developed via experimental evolution. Here, we examine physiological responses and bacterial community composition (using 16S rRNA gene metabarcoding) in cultures of 10 heat-evolved (SS) and 9 wild-type (WT) strains, which had been exposed for 6 years to 31 °C and 27 °C, respectively. We also examine whether the associated bacterial communities were affected by a three-week reciprocal transplantation to both temperatures. The SS strains had bacterial communities with lower diversities that showed more stability and lower variability when exposed to elevated temperatures compared with the WT strains. Amplicon sequence variants (ASVs) of the bacterial genera , , and were significantly more associated with the SS strains compared with the WT strains. WT strains showed higher abundance of ASVs assigned to the genera and . We hypothesize that these compositional differences in associated bacterial communities between SS and WT strains also contribute to the thermal tolerance of the microalgae. Future research should explore functional potential between bacterial communities using metagenomics to unravel specific genomic adaptations.
耐热珊瑚共生藻 C1（Symbiodiniaceae）菌株先前已通过实验进化得到。在这里，我们研究了在分别暴露于 31°C 和 27°C 下 6 年的 10 株热进化（SS）和 9 株野生型（WT）菌株的生理响应和细菌群落组成（使用 16S rRNA 基因宏条形码）。我们还研究了相关细菌群落是否受到为期三周的温度互传移植的影响。与 WT 菌株相比，SS 菌株的细菌群落多样性较低，在暴露于高温时表现出更高的稳定性和更低的可变性。与 WT 菌株相比，细菌属 、 、 和 的扩增子序列变异体（ASVs）与 SS 菌株的相关性更高。WT 菌株显示出更高丰度的 ASVs，这些 ASVs被分配到属 和 。我们假设，SS 和 WT 菌株之间相关细菌群落的这些组成差异也有助于微藻的耐热性。未来的研究应该使用宏基因组学探索细菌群落之间的功能潜力，以揭示特定的基因组适应性。
