中科院海洋生物資源可持續(xù)利用重點實驗室（依托于南海海洋研究所）秦啟偉研究員領(lǐng)導(dǎo)的團隊，在海洋病毒編碼的miRNA研究方面取得突破性進(jìn)展,。團隊成員閆陽博士等首次鑒定并驗證了一種新的海洋病毒——石斑魚虹彩病毒能夠編碼功能性miRNA,。研究成果已于近日發(fā)表在國際知名的綜合類學(xué)術(shù)期刊《公共科學(xué)圖書館—綜合》（Yan ,et al. 2011. Identification of a Novel Marine Fish Virus, Singapore Grouper Iridovirus-Encoded MicroRNAs Expressed in Grouper Cells by Solexa Sequencing. PloS ONE. 2011. 6(4): e19148）。
虹彩病毒（iridovirus）是一類廣泛感染無脊椎和低等水生脊椎動物的大分子DNA病毒,，對海洋野生動物種群和海水養(yǎng)殖動物造成極大威脅,。石斑魚虹彩病毒（Singapore grouper iridovirus, SGIV）是該團隊從海水養(yǎng)殖石斑魚體中分離出的一種新的高致病性虹彩病毒，是中國和東南亞海水養(yǎng)殖魚類最重要的病毒性病原之一,。然而,，目前對SGIV感染致病的分子機理尚不十分清楚，缺乏有效的防治手段,。
病毒編碼的miRNA研究方興未艾，因其長度較短,、沒有免疫原性等特點而成為治療疾病的新型靶點,。團隊為揭示SGIV在其感染過程中是否編碼miRNA，將感染了SGIV不同時期的石斑魚胚胎細(xì)胞混合后構(gòu)建小RNA庫,，進(jìn)行Illumina/Solexa RNA深度測序,。通過一系列生物信息學(xué)分析，最終確定16條SGIV編碼的miRNA序列,，其中一條與2型單純皰疹病毒編碼的miR-H4-5p具有高度同源性,，提示miRNA在遠(yuǎn)緣病毒種中具有一定的保守性。這16個新發(fā)現(xiàn)的miRNA散在分布于SGIV基因組中,，其中三個定位于ORF057L,。同時發(fā)現(xiàn)SGIV編碼的miRNA在其3' 端或5' 端存在序列或長度的異質(zhì)性，可能會影響其與靶基因的識別,。熒光定量PCR及熒光素酶報告基因分析了這16個miRNA的表達(dá)水平和潛在的生物學(xué)活性,，證實其中11個miRNA確實存在于SGIV感染的石斑魚胚胎細(xì)胞中，并發(fā)揮生物學(xué)功能,。
以前只有人類和哺乳動物編碼miRNA的研究報道,，其中報道較多的為皰疹病毒科的各成員。該研究首次在國際上證實了海洋病毒也可以編碼功能性miRNA,，將miRNA研究推向了一個新的層次,。
該項研究受到國家杰出青年基金、國家重點基礎(chǔ)研究計劃（“973”計劃）和中科院知識創(chuàng)新工程重要方向項目資助,。(生物谷 Bioon.com)
doi:10.1371/journal.pone.0019148
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Identification of a Novel Marine Fish Virus, Singapore Grouper Iridovirus-Encoded MicroRNAs Expressed in Grouper Cells by Solexa Sequencing
Yang Yan1, Huachun Cui1, Songshan Jiang1, Youhua Huang2, Xiaohong Huang2, Shina Wei2, Weiyi Xu1, Qiwei Qin2
Background MicroRNAs (miRNAs) are ubiquitous non-coding RNAs that regulate gene expression at the post-transcriptional level. An increasing number of studies has revealed that viruses can also encode miRNAs, which are proposed to be involved in viral replication and persistence, cell-mediated antiviral immune response, angiogenesis, and cell cycle regulation. Singapore grouper iridovirus (SGIV) is a pathogenic iridovirus that has severely affected grouper aquaculture in China and Southeast Asia. Comprehensive knowledge about the related miRNAs during SGIV infection is helpful for understanding the infection and the pathogenic mechanisms. Methodology/Principal Findings To determine whether SGIV encoded miRNAs during infection, a small RNA library derived from SGIV-infected grouper (GP) cells was constructed and sequenced by Illumina/Solexa deep-sequencing technology. We recovered 6,802,977 usable reads, of which 34,400 represented small RNA sequences encoded by SGIV. Sixteen novel SGIV-encoded miRNAs were identified by a computational pipeline, including a miRNA that shared a similar sequence to herpesvirus miRNA HSV2-miR-H4-5p, which suggests miRNAs are conserved in far related viruses. Generally, these 16 miRNAs are dispersed throughout the SGIV genome, whereas three are located within the ORF057L region. Some SGIV-encoded miRNAs showed marked sequence and length heterogeneity at their 3鈥?and/or 5鈥?end that could modulate their functions. Expression levels and potential biological activities of these viral miRNAs were examined by stem-loop quantitative RT-PCR and luciferase reporter assay, respectively, and 11 of these viral miRNAs were present and functional in SGIV-infected GP cells.ConclusionsOur study provided a genome-wide view of miRNA production for iridoviruses and identified 16 novel viral miRNAs. To the best of our knowledge, this is the first experimental demonstration of miRNAs encoded by aquatic animal viruses. The results provide a useful resource for further in-depth studies on SGIV infection and iridovirus pathogenesis.
