Table3_Differential expression of miRNAs in the body wall of the sea cucumber Apostichopus japonicus under heat stress.XLSX

MicroRNAs, as one of the post-transcriptional regulation of genes, play an important role in the development process, cell differentiation and immune defense. The sea cucumber Apostichopus japonicus is an important cold-water species, known for its excellent nutritional and economic value, which usually encounters heat stress that affects its growth and leads to significant economic losses. However, there are few studies about the effect of miRNAs on heat stress in sea cucumbers. In this study, high-throughput sequencing was used to analyze miRNA expression in the body wall of sea cucumber between the control group (CS) and the heat stress group (HS). A total of 403 known miRNAs and 75 novel miRNAs were identified, of which 13 miRNAs were identified as significantly differentially expressed miRNAs (DEMs) in response to heat stress. A total of 16,563 target genes of DEMs were predicted, and 101 inversely correlated target genes that were potentially regulated by miRNAs in response to heat stress of sea cucumbers were obtained. Based on these results, miRNA-mRNA regulatory networks were constructed. The expression results of high-throughput sequencing were validated in nine DEMs and four differentially expressed genes (DEGs) by quantitative real-time polymerase chain reaction (RT-qPCR). Moreover, pathway enrichment of target genes suggested that several important regulatory pathways may play an important role in the heat stress process of sea cucumber, including ubiquitin-mediated proteolysis, notch single pathway and endocytosis. These results will provide basic data for future studies in miRNA regulation and molecular adaptive mechanisms of sea cucumbers under heat stress.

微小RNA（MicroRNAs，miRNAs）作为基因转录后调控的重要分子类群，在生物发育、细胞分化以及免疫防御过程中发挥关键调控作用。仿刺参（Apostichopus japonicus）是一类重要的冷水性水产物种，兼具优异的营养价值与经济价值，但在养殖过程中常遭遇热应激，该应激会抑制其生长并造成显著的经济损失。然而，目前关于miRNA对仿刺参热应激影响的相关研究仍较为匮乏。本研究采用高通量测序技术，对对照组（CS）与热应激组（HS）仿刺参体壁组织中的miRNA表达谱进行分析。本研究共鉴定出403个已知miRNA与75个新预测miRNA，其中13个miRNA被鉴定为响应热应激的显著差异表达miRNA（differentially expressed miRNAs, DEMs）。本研究共预测得到16563个DEMs的靶基因，并筛选出101个与DEMs表达呈负相关的潜在靶基因，这些基因可能参与miRNA介导的仿刺参热应激响应调控。基于上述结果，本研究构建了miRNA-mRNA调控网络。本研究采用实时荧光定量聚合酶链反应（quantitative real-time polymerase chain reaction, RT-qPCR），对9个DEMs与4个差异表达基因（differentially expressed genes, DEGs）的高通量测序表达结果进行了验证。此外，靶基因的通路富集分析结果显示，多条重要调控通路可能参与仿刺参的热应激过程，包括泛素介导的蛋白水解通路、Notch单信号通路以及胞吞作用。本研究结果可为后续仿刺参热应激下miRNA调控机制及分子适应机制的相关研究提供基础数据。