Abstract：
During pond culture or intensive culture system of crabs (mainly Eriocheir sinensis, Portunus trituberculatus and Scylla paramamosain), high-density farming has typically contributed to a higher limb autotomy level in juvenile animals, especially in S. paramamosain which has a high level of cannibalism. Due to the high limb autotomy level, the survival and growth rates in S. paramamosain farming are restricted, which limit the growth of the mud crab farming industry. MicroRNAs (miRNAs) are small noncoding RNAs that regulate a series of biological processes including innate immune responses by post-transcriptional suppression of their target genes. MiRNAs are believed to be crucial for innate immune process of host wound healing. Many miRNAs have been verified to be required in host immune responses to repair wound and to defense pathogen after tissue damage. However, to our best knowledge, the miRNAs functions of crustacean innate immune reactions against injury induced by limb autotomy have not been studied yet. Here in this study, for the first time, miRNAs involved in the S. paramamosain immune reactions against injury induced by cheliped autotomy were obtained by high-throughput sequencing. A total of 575 miRNAs (518 known miRNAs and 57 novel predicted miRNAs) were obtained, of which 141 differentially expressed microRNAs (93 up-regulated microRNAs and 48 down-regulated microRNAs) were revealed to be modified against cheliped autotomy, and the qPCR results of randomly selected miRNAs confirmed the expression patterns in the miRNAs sequencing data. Numerous immune-related target genes associated with innate immune system were mediated by miRNAs to induce host humoral immune and cellular immune defense to minimize acute physical damage. Furthermore, the genes expression in hemolymph coagulation and melanization pathways, as well as Toll and Imd signaling pathways were mediated by miRNAs to activate host immune responses including melanization and antimicrobial peptides for rapid wound healing and killing invaded pathogens. These results will help to understand injury-induced immune responses in crabs and to develop an effective control strategy of autotomy rate in crabs farming.
摘要：
在螃蟹的池塘养殖或密集养殖系统中（主要是中华绒螯蟹，三疣梭子蟹和青蟹），高密度养殖通常有助于幼年动物的较高肢体自断水平，特别是在S.paramamosain中，它具有很高的食人族。由于肢体自切水平较高，paramamosain养殖的存活率和增长率受到限制，这限制了泥蟹养殖业的增长。MicroRNAs（miRNA）是通过转录后抑制其靶基因来调节一系列生物过程，包括先天性免疫反应的小的非编码RNA。miRNA被认为对于宿主伤口愈合的先天性免疫过程至关重要。许多miRNA已被证实在宿主免疫应答中需要修复伤口和在组织损伤后防御病原体。然而,据我们所知，目前尚未研究甲壳动物对肢体自断损伤的先天性免疫反应的miRNAs功能。在这项研究中，第一次,通过高通量测序获得了参与S.paramamosain免疫反应的miRNAs，以抵抗由cheliped自断诱导的损伤。共获得575个miRNA（518个已知miRNA和57个新的预测miRNA），其中141个差异表达的microRNAs（93个上调的microRNAs和48个下调的microRNAs）被发现被修饰以抵抗绒毛自断，和随机选择的miRNA的qPCR结果证实了miRNA测序数据中的表达模式。许多与先天免疫系统相关的免疫相关的靶基因由miRNA介导，以诱导宿主体液免疫和细胞免疫防御，从而最大程度地减少急性物理损伤。此外，血淋巴凝固和黑化途径中的基因表达，以及Toll和Imd信号通路由miRNA介导以激活宿主免疫应答,包括黑化和抗菌肽用于快速伤口愈合和杀死侵入的病原体。这些结果将有助于了解螃蟹损伤引起的免疫反应，并制定有效的螃蟹养殖自切率控制策略。
