甲壳动物中白斑综合征病毒来源小RNA的特征及其保守富集的结构基础
CHARACTERISTICS OF WHITE SPOT SYNDROME VIRUS-DERIVED SMALL RNAS IN CRUSTACEANS AND THE STRUCTURAL BASIS OF THEIR CONSERVED ENRICHMENT
-
摘要: 为系统研究不同甲壳动物宿主中白斑综合征病毒(White spot syndrome virus, WSSV)来源的小干扰RNA (virus-derived small interfering RNA, vsiRNA)的产生特征, 本研究整合分析了NCBI公共数据库中公开可获得的甲壳动物small RNA与miRNA测序数据。对下载的测序数据进行预处理后, 以零错配策略将其严格比对至WSSV参考基因组。基于比对结果, 选取南美白对虾(Penaeus vannamei)、长毛对虾(Penaeus penicillatus)、拟穴青蟹(Scylla paramamosain)、欧洲岸蟹(Carcinus maenas)和克氏原螯虾(Procambarus clarkii) 5个代表性宿主, 对其WSSV来源的vsiRNA特征进行分析。结果表明, 南美白对虾和欧洲岸蟹中可检测到大量WSSV来源vsiRNA, 其长度主要集中于22 nt, 正、负链均有分布, 并呈现典型的小干扰RNA特征; 而在其余3种宿主中, WSSV来源vsiRNA数量较少, 长度分布较分散, 未形成明显主峰, 表明不同宿主应对病毒的RNAi反应能力有所差别。进一步分析发现, 尽管不同宿主中WSSV来源vsiRNA的整体分布模式存在差异, 但在多个物种中均可观察到WSSV基因组上相同区域出现vsiRNA富集现象。对该富集区域的序列与结构特征分析表明, 其具有较高的GC含量、较低的最小自由能, 并富集形成双链或发卡结构的保守序列基序, 表明稳定的RNA二级结构可能有助于增强RNAi机制对该区域的识别与加工。本研究基于公共数据库数据揭示了5种甲壳动物宿主中WSSV来源vsiRNA的产生特征, 为理解甲壳动物对WSSV感染的RNAi免疫响应提供了数据基础, 并为后续基于RNAi的防控策略研究提供了理论参考。Abstract: To systematically investigate the characteristics of white spot syndrome virus (WSSV)-derived small interfering RNAs (vsiRNAs) in different crustacean hosts, publicly available small RNA and miRNA sequencing datasets of crustaceans were retrieved and analyzed from the NCBI SRA database. After data preprocessing, all reads were stringently mapped to the WSSV reference genome using a zero-mismatch strategy. Based on the mapping results, five representative crustacean hosts, Penaeus vannamei, P. penicillatus, Scylla paramamosain, Carcinus maenas, and Procambarus clarkii, were selected for analysis of WSSV-derived vsiRNA characteristics. The results showed that abundant WSSV-derived vsiRNAs were detected in P. vannamei and C. maenas, with a predominant length of 22 nt and distribution on both the positive and negative strands of the viral genome, exhibiting typical features of small interfering RNAs. In contrast, the other three hosts displayed much lower amounts of WSSV-derived vsiRNAs with dispersed length distributions and no obvious dominant peak. Although overall distribution patterns of WSSV-derived vsiRNAs varied among hosts, shared genomic regions of WSSV consistently exhibited vsiRNA enrichment across multiple species. Sequence and structural features of these hotspot regions, including elevated GC content, lower minimum free energy, and enrichment of conserved motifs forming double-stranded or hairpin structures, suggest that RNA secondary structure may contribute to the preferential processing of these regions by the RNAi pathway. This study provides a comparative overview of WSSV-derived vsiRNA characteristics in five crustacean species based on public sequencing data, and offers insights into crustacean RNAi responses to WSSV infection and a reference for future studies on antiviral mechanisms and RNAi-based disease control strategies.
下载: