鬼手海葵(Aiptasia pulchella)白化恢复后的基因表达差异

Difference in gene expression of Aiptasia pulchella after albino recovery

海葵白化是由于海葵失去体内共生的虫黄藻和(或)共生的虫黄藻失去体内色素而导致海葵变白的生态现象。为探究鬼手海葵(Aiptasia pulchella)白化和白化恢复后相关的分子机制,本研究对海葵进行慢性热胁迫处理,以白化海葵和白化恢复后的海葵为研究对象,采用2代IIlumina Hi-seq测序技术进行转录组测序,探究两者在基因表达水平方面的差异变化,分别获得50109686和43163786条Clean reads,注释后获得24565和24157个Unigene。比较转录组分析结果显示,白化海葵与白化恢复后的海葵之间存在214个差异表达基因,其中白化海葵的高表达基因有101个,白化恢复后海葵的高表达基因有113个,这些差异表达基因主要与DNA复制、新陈代谢、离子转运和胶原蛋白有关。对不同处理所涉及的全部28050个表达基因进行基因集富集分析(gene set enrichment analysis,GSEA),结果发现,白化海葵在胶原蛋白和离子转运方面显著富集表达,白化恢复后的海葵在核酸修复方面显著富集表达,推测这些生物学过程在海葵白化和白化后修复过程中发挥重要作用。本研究获得的转录组数据和研究结果初步揭示了海葵共生体系在共生失衡后进行适应性调节的分子机制,为海葵及珊瑚共生体系应对环境变化的适应性机制研究提供了理论依据。

Anemone bleaching can be defined generally as a decline in the population of the symbiotic algae,a reduction in the pigment content of the algae,or both.In order to study the molecular mechanism of Aiptasia pulchella during bleaching and recovered phage affected by chronic heat stress,transcriptome analysis by Illumina Hi-seq of bleaching and recovered A.pulchella was carried out on 50109686 and 43163786 clean reads,which were annotated as 24565 and 24157 unigenes,respectively.The results of comparative transcriptome analysis showed that there were 214 differentially expressed genes(DEGs),including 101 that were significantly highly expressed in bleaching A.pulchella and 113 in recovered A.pulchella.These genes were mainly involved in DNA replication,metabolism,ion transport,and collagen.Gene set enrichment analysis(GSEA)of all 28,050 expressed genes showed that collagen and ion transport were enriched in bleaching A.pulchella,while nucleotide repair was enriched in recovered A.pulchella.We speculate that these biological processes may play an important role in the bleaching and recovering phases of anemone.The main findings obtained in this study preliminarily reveal the molecular mechanism of adaptive regulation of anemone holobiont after symbiotic imbalance,providing a theoretical basis for the adaptive mechanism of anemone and coral symbiosis system in response to environmental changes.