Key Laboratory of Conservation Biology for Endangered Wildlife of Ministry of Education, Zhejiang University, No. 388, Yuhangtang Road, Xihu District, Hangzhou 310058, People's Republic of China.
Fish Shellfish Immunol. 2012 Sep;33(3):575-81. doi: 10.1016/j.fsi.2012.06.014. Epub 2012 Jul 11.
RNA interference (RNAi) mediated by microRNA (miRNA) is an evolutionarily conserved mechanism of posttranscriptional gene regulation in all eukaryotes, involving in natural antiviral immunity. The RNAase III Drosha is a key component for miRNA maturation. To date, however, the roles of Drosha in virus infection remain to be addressed. In this study, the Drosha was characterized in Marsupenaeus japonicus shrimp. The sequence analysis revealed that the shrimp Drosha gene encoded a 1081-amino-acid peptide, which comprised two tandem ribonuclease III C terminal domains and a double-stranded RNA binding motif. The shrimp Drosha was homologous with those of other animal species. The quantitative RT-PCR analysis revealed that the Drosha gene was highly expressed in lymphoid organ and was significantly up-regulated in response to WSSV challenge, suggesting that the Drosha was involved in the antiviral immunity of shrimp. The results showed that the knock down of Drosha gene led to the defect of miRNA maturation, and subsequent higher virus loads in shrimp. Our study presented that Drosha played important roles in the antiviral defense of shrimp.
RNA 干扰 (RNAi) 介导的 microRNA (miRNA) 是所有真核生物中一种保守的转录后基因调控机制，涉及天然抗病毒免疫。RNAase III Drosha 是 miRNA 成熟的关键组成部分。然而，迄今为止，Drosha 在病毒感染中的作用仍有待解决。在本研究中，我们对日本沼虾中的 Drosha 进行了表征。序列分析表明，虾 Drosha 基因编码一个 1081 个氨基酸的肽，它包含两个串联的核糖核酸酶 III C 端结构域和一个双链 RNA 结合基序。虾 Drosha 与其他动物物种的 Drosha 具有同源性。定量 RT-PCR 分析显示，Drosha 基因在淋巴器官中高度表达，并在 WSSV 挑战时显著上调，表明 Drosha 参与了虾的抗病毒免疫。结果表明，Drosha 基因的敲低导致 miRNA 成熟缺陷，随后虾中的病毒载量增加。我们的研究表明 Drosha 在虾的抗病毒防御中发挥重要作用。
