Nitrite is one of the most common pollutants in high-density aquaculture or in recirculated aquaculture systems. In this study, gene and miRNA expression dynamics were investigated for unveiling the genetic regulation of Eriocheir sinensis in response to acute nitrite stress. Two groups of E. sinensis with different vitality of appendages (i.e., NG and DG) were treated with nitrite-N in 6 and 24 h, respectively. A number of differentially expressed (DE) genes and miRNAs were detected in the pairwise comparisons of the two groups. We found that the DE genes and the target genes of DE miRNAs were significantly enriched into some key pathways, such as metabolic pathways, MAPK signaling pathway, and nitrogen metabolism. Notably, the number of DE genes identified from the pairwise comparison of MNG vs. FNG (NG groups at 6 h and 12 h, respectively) was much larger than that identified from MDG vs. FDG (FG groups at 6 h and 12 h, respectively), indicating that the individuals from strong vitality group had genetic superiority for tolerance of nitrite stress. The similar trend was also observed from the identification of DE miRNAs. Some key genes (e.g., hsp70, mtnd2, act7, hspg2, cam-1) involved in signaling transduction, oxidative phosphorylation, and energy metabolism were detected in this study. Besides, several miRNAs (miR-31, miR-215, miR-142-x) that mediate the calmodulin related genes were also identified, inferring that calcium signaling pathway participates in the responses to nitrite stress in crabs. This study revealed the mRNA and miRNA expression patterns of Chinese mitten crab under sustained nitrite stress and provided the genetic basis for the molecular selective breeding.

亚硝酸盐是高密度水产养殖或循环水产养殖系统中最常见的污染物之一。在这项研究中，研究了基因和miRNA表达动力学以揭示中华绒螯蟹对急性亚硝酸盐胁迫的遗传调控。两组中华绒螯蟹分别用6和24小时的亚硝酸盐-N处理具有不同生命力的附件（即NG和DG）。在两组的成对比较中检测到许多差异表达（DE）基因和miRNA。我们发现DE miRNA的DE基因和靶基因明显丰富了一些关键途径，例如代谢途径，MAPK信号传导途径和氮代谢。值得注意的是，从MNG与FNG的成对比较（分别在6 h和12 h的NG组）中鉴定出的DE基因数量远大于从MDG vs FDG（在6 h和12 h的FG组，分别表明，具有强大活力的人群在亚硝酸盐胁迫耐受性方面具有遗传优势。从DE miRNA的鉴定中也观察到了类似的趋势。一些关键基因（例如在这项研究中检测到hsp70，mtnd2，act7，hspg2，cam-1）参与信号转导，氧化磷酸化和能量代谢。此外，还鉴定了几种介导钙调蛋白相关基因的miRNA（miR-31，miR-215，miR-142-x），推测钙信号通路参与了蟹对亚硝酸盐胁迫的响应。这项研究揭示了中华绒螯蟹在持续的亚硝酸盐胁迫下的mRNA和miRNA表达模式，为分子选择育种提供了遗传基础。