French Research Institute for Exploitation of the Sea, Ifremer DYNECO PELAGOS, 29280, Plouzané, France.
CNRS, Sorbonne Université, UC, UaCh, UMI 3614, Evolutionary Biology and Ecology of Algae, Station Biologique de Roscoff, CS 90074, 29688, Roscoff, France.
Sci Rep. 2020 Apr 10;10(1):6182. doi: 10.1038/s41598-020-63326-8.
Harmful algal blooms are caused by specific members of microbial communities. Understanding the dynamics of these events requires comparing the strategies developed by the problematic species to cope with environmental fluctuations to the ones developed by the other members of the community. During three consecutive years, the meta-transcriptome of micro-eukaryote communities was sequenced during blooms of the toxic dinoflagellate Alexandrium minutum. The dataset was analyzed to investigate species specific gene expression dynamics. Major shifts in gene expression were explained by the succession of different species within the community. Although expression patterns were strongly correlated with fluctuation of the abiotic environment, and more specifically with nutrient concentration, transcripts specifically involved in nutrient uptake and metabolism did not display extensive changes in gene expression. Compared to the other members of the community, A. minutum displayed a very specific expression pattern, with lower expression of photosynthesis transcripts and central metabolism genes (TCA cycle, glucose metabolism, glycolysis…) and contrasting expression pattern of ion transporters across environmental conditions. These results suggest the importance of mixotrophy, cell motility and cell-to-cell interactions during A. minutum blooms.
有害藻华是由微生物群落中的特定成员引起的。了解这些事件的动态需要将有问题的物种为应对环境波动而制定的策略与群落中其他成员制定的策略进行比较。在连续三年的时间里，对有毒甲藻亚历山大藻的微真核生物群落的元转录组进行了测序。对该数据集进行了分析，以研究物种特异性基因表达动态。群落中不同物种的演替解释了基因表达的主要变化。尽管表达模式与非生物环境的波动密切相关，特别是与营养浓度密切相关，但专门参与营养吸收和代谢的转录本并没有显示出基因表达的广泛变化。与群落中的其他成员相比，亚历山大藻表现出非常特殊的表达模式，光合作用转录物和中心代谢基因（三羧酸循环、葡萄糖代谢、糖酵解……）的表达水平较低，而在不同环境条件下离子转运蛋白的表达模式则相反。这些结果表明，在亚历山大藻藻华期间，混养、细胞运动和细胞间相互作用非常重要。
