Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture of P. R. China, Shanghai Ocean University, Shanghai 201306, China.
J Fish Biol. 2013 Nov;83(5):1234-48. doi: 10.1111/jfb.12219.
In this study, the dicer gene (designated as cidicer) was identified and characterized from grass carp Ctenopharyngodon idella. The complementary DNA (cDNA) of cidicer contained an open reading frame (ORF) of 5646 nucleotides (nts) encoding a putative protein of 1881 amino acids (aa). The deduced Dicer protein contained all known functional domains identified in other organisms. Tissue tropism analysis indicated that cidicer is abundantly expressed in brain, gill, head kidney, liver, spleen, heart, muscle and intestine. In the C. idella kidney (CIK) cells, messenger RNA (mRNA) expression of cidicer was significantly up-regulated at 24 h (6·36-fold, P < 0·01) after grass carp reovirus (GCRV) infection, and its transcriptional expression level was also transiently induced to a high level (6·54-fold, P < 0·01) at 2 h post-stimulation of synthetic double-stranded polyinosinic-polycytidylic potassium salt [poly(I:C)]. In vivo analysis further showed that the expression of cidicer mRNA in the liver was induced to a significantly high level at 12 h (8·46-fold, P < 0·01), and then dropped to normal level at 72 h post-challenge with GCRV. The transcriptional expression pattern of cidicer in the spleen tissue was similar to that of liver tissue upon GCRV challenge. These results collectively implied that the identified cidicer was an inducible gene responding to viral infection both in vitro and in vivo, and the data would shed light on the interaction between RNA interference (RNAi) antiviral pathway and aquareovirus infection.
在这项研究中，我们从草鱼（Ctenopharyngodon idella）中鉴定并表征了 Dicer 基因（命名为 cidicer）。cidicer 的 cDNA 包含一个 5646 个核苷酸（nts）的开放阅读框（ORF），编码一个 1881 个氨基酸（aa）的假定蛋白。推导的 Dicer 蛋白包含在其他生物体中鉴定出的所有已知功能结构域。组织嗜性分析表明，cidicer 在脑、鳃、头肾、肝、脾、心、肌肉和肠中大量表达。在草鱼呼肠孤病毒（GCRV）感染后 24 小时（6.36 倍，P < 0.01），草鱼肾脏（CIK）细胞中 cidicer 的信使 RNA（mRNA）表达显著上调，其转录表达水平也被短暂诱导至高水平（6.54 倍，P < 0.01），在合成双链聚肌胞苷酸钾[poly（I：C）]刺激后 2 小时。体内分析进一步表明，感染 GCRV 后 12 小时（8.46 倍，P < 0.01），肝组织中 cidicer mRNA 的表达被诱导至显著高水平，然后在 GCRV 攻击后 72 小时降至正常水平。脾组织中 cidicer 的转录表达模式与肝组织相似。这些结果共同表明，鉴定出的 cidicer 是一种可诱导基因，能够在体外和体内对病毒感染产生反应，该数据将有助于揭示 RNA 干扰（RNAi）抗病毒途径与 Aquareovirus 感染之间的相互作用。
