Transcriptional response to sulfide in the Echiuran Worm Urechis unicinctus by digital gene expression analysis.
Transcriptional response to sulfide in the Echiuran Worm Urechis unicinctus by digital gene expression analysis.
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通过数字基因表达分析研究 Echiuran 蠕虫 Urechis unicinctus 对硫化物的转录反应
DOI：
10.1186/s12864-015-2094-z
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发表时间：
2015-10-21
期刊：
影响因子：
4.4
通讯作者：
Liu J
中科院分区：
文献类型：
--
作者：
Liu X;Zhang L;Zhang Z;Ma X;Liu J
单环刺鳅（Urechis unicinctus）是一种寄生于沿海滩涂U形洞穴中的棘尾类蠕虫，是东北亚地区重要的经济和生态无脊椎动物，在动物进化研究、海岸沉积物改良和海洋药物开发等方面具有潜在的应用价值。此外，该虫还能耐受和利用已知的有毒物质硫化物。然而，目前对U. unicinctus对硫化物的反应是由于其遗传信息的缺乏。在这项研究中，我们进行了Illumina测序，以获得第一个单环刺鳅转录组数据。组装测序读数，然后使用针对Nr、Nt、Swiss-Prot、KEGG和COG的blast搜索进行注释。将来自四个数字基因表达（DGE）文库的干净标签定位到美国。unicinctus转录组。然后进行DGE分析和功能注释，以揭示其对硫化物的响应。采用实时荧光定量PCR技术对12个候选基因的表达进行了验证。根据DGE分析对qRT-PCR的结果进行回归，并报告每个结果的相关系数和p值。在这里，我们首先提出了一个草案的U。使用Illumina HiSeqTM 2000平台对unicinctus转录组进行测序，组装了52，093个独特序列，平均长度为738 bp，N50为1131 bp。基于Nr、Nt、Swiss-Prot、KEGG和COG数据库，约51.6%的转录组被功能注释。在转录组的基础上，进行数字化基因表达分析，检测硫暴露6、24和48 h时的转录响应，最终在6、24和48 h文库中分别筛选出1705、1181和1494个差异表达基因，并进一步进行途径分析。在U. unicinctus中，某些已知的硫化物相关途径的改变表明对硫化物的响应发生了类似的变化。其中，糖酵解途径和PIDD途径是较为独特的途径，并被认为在硫胁迫耐受中起着重要作用。单环的这些结果有助于解释植物的耐硫解毒机制。本文的在线版本（doi：10.1186/s12864 - 015 - 2094-z）包含补充材料，可供授权用户使用。
Urechis unicinctus, an echiuran worm inhabiting the U-shaped burrows in the coastal mud flats, is an important commercial and ecological invertebrate in Northeast Asian countries, which has potential applications in the study of animal evolution, coastal sediment improvement and marine drug development. Furthermore, the worm can tolerate and utilize well-known toxicant-sulfide. However, knowledge is limited on the molecular mechanism of U. unicinctus responding to sulfide due to deficiency of its genetic information. In this study, we performed Illumina sequencing to obtain the first Urechis unicinctus transcriptome data. Sequenced reads were assembled and then annotated using blast searches against Nr, Nt, Swiss-Prot, KEGG and COG. The clean tags from four digital gene expression (DGE) libraries were mapped to the U. unicinctus transcriptome. DGE analysis and functional annotation were then performed to reveal its response to sulfide. The expressions of 12 candidate genes were validated using quantitative real-time PCR. The results of qRT-PCR were regressed against the DGE analysis, with a correlation coefficient and p-value reported for each of them. Here we first present a draft of U. unicinctus transcriptome using the Illumina HiSeqTM 2000 platform and 52,093 unique sequences were assembled with the average length of 738 bp and N50 of 1131 bp. About 51.6 % of the transcriptome were functionally annotated based on the databases of Nr, Nt, Swiss-Prot, KEGG and COG. Then based on the transcriptome, the digital gene expression analysis was conducted to examine the transcriptional response to sulfide during 6, 24 and 48 h exposure, and finally 1705, 1181 and 1494 tag-mapped genes were identified as differentially expressed genes in the 6-h, 24-h and 48-h libraries, then were further subjected to pathway analyses. In the DGE database of U. unicinctus, the alterations in certain known sulfide-related pathways indicate similar changes in response to sulfide. For more than 80 % of the identified pathway members, this is the first report on their association with sulfide stress, among which glycolysis pathway and PIDD involving pathways were unique and discussed in details, and were thought to play important roles in the sulfide tolerance of U. unicinctus. All the results are helpful to explain the mechanism of sulfide tolerance and detoxification. The online version of this article (doi:10.1186/s12864-015-2094-z) contains supplementary material, which is available to authorized users.