单环刺螠响应双酚A胁迫的转录组分析

Transcriptomics analysis of echiuran worm(Urechis unicinctus)in response to BPA stress

为探究环境内分泌干扰物双酚A(bisphenol A,BPA)对海洋底栖动物单环刺螠(Urechis unicinctus)毒性影响的分子机制,采用高通量测序平台Illumina Hiseq 2500分别对BPA暴露后和对照组单环刺螠(体质量为17.3 g±1.5 g)的体腔细胞转录组进行测序及比较分析。结果表明:高通量测序共获得13.74 Gb高质量数据,组装得到108262个转录本和30882条单基因序列(Unigene),平均长度为1380 bp,N50长度为2549 bp;共有14581个Unigene得到注释,其中7242个Unigene注释到KEGG数据库,归类于284个代谢通路;BPA胁迫下筛选出1073个差异表达基因,包括649个基因表达上调和424个基因表达下调;GO功能分类注释显示,差异基因主要涉及催化、结合、抗氧化、转运体、信号转导和电子载体等分子功能;KEGG富集分析显示,163个基因被注释到151条KEGG通路中,富集程度最显著的3个通路为真核生物核糖体生物合成、谷胱甘肽代谢和细胞色素P450对外源物质代谢。研究表明,BPA胁迫会对单环刺螠体腔细胞的合成、免疫及解毒代谢产生显著影响,获得的单环刺螠体腔细胞转录组数据可为揭示单环刺螠的抗逆机制,以及研究环境内分泌干扰物对海洋生物的毒性提供参考依据。

To explore the molecular mechanism of bisphenol A(BPA)toxicity effects on echiuran worm(Urechis unicinctus),echiuran worm with body weight of(17.3±1.5)g was exposed to 3 mg/L BPA(0.15%of anhydrous ethanol as co-solvent)and sea water(control group)and then the transcriptome sequencing was adopted for coelomocytes of the echiuran worm under an Illumina Hiseq 2500 platform.The results showed that 13.74 Gb of high-quality sequencing data were obtained with Q30≥93.02%,108262 transcripts and 30882 Unigene were assembled,with average length of 1380 bp and N50 of 2549 bp.Eight data bases(NR,GO,COG,Swiss-Prot,KOG,KEGG,eggNOG4.5 and Pfam)were selected for the Unigene annotation,with 14581 annotated Unigene,in which 7242 Unigene were annotated to genes in KEGG database,further being classified into 284 metabolic pathways.Gene differential expression analysis indicated that 1073 transcripts were differentially expressed in response to BPA stress,including 649 up-regulated genes and 424 down-regulated genes.GO functional classification showed that the differentially expressed genes were primarily involved in the biological process of catalytic activity,binding,antioxidant,transporter,signal transducer and electron carrier.The KEGG enrich analysis revealed that 163 genes were mapped into 151 pathways,and three most significantly enriched pathways were ribosome biogenesis in eukaryotes,glutathione metabolism,and metabolism of xenobiotics by cytochrome P450.The synthesis,immonology and detoxification metabolism of the coelomocytes elucidated the adverse effects of BPA on echiuran worm.The findings provide the reference data with the marine biotoxicity research of environmental endocrine disruptors(EEDs)and anti-stress mechanism of echiuran worm.