Transcriptomic characterization of zebrafish larvae in response to mercury exposure
Transcriptomic characterization of zebrafish larvae in response to mercury exposure
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斑马鱼幼虫对汞暴露的反应的转录组特征
DOI：
10.1016/j.cbpc.2016.12.006
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发表时间：
2017-02-01
影响因子：
3.9
通讯作者：
Zhong, Shan
中科院分区：
文献类型：
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作者：
Lu, Xing;Xiang, Ying;Zhong, Shan
汞是一种广泛存在于水环境中的有毒物质，可对鱼类造成有害影响。虽然一些汞调控基因已在成鱼中进行了研究，但幼鱼对急性汞暴露的转录反应还不清楚。在这项研究中，RNA测序被用来检查在低浓度的氯化汞暴露下，从24至120 hpf的斑马鱼幼虫发育的转录变化。我们的初步结果显示，从测序文库中获得了总计1.4259亿个原始读段，约86%的处理读段被映射到斑马鱼的参考基因组。差异表达分析鉴定了391个上调和87个下调基因。基因本体富集分析表明，大部分差异表达基因与细胞过程、代谢过程、多细胞生物过程、生物调节、色素沉着、对刺激的反应等密切相关。京都基因百科全书和基因组途径富集分析表明，抗原加工和呈递是最显著富集的途径。此外，我们还鉴定了一个新的、敏感的汞诱导的ABCB（ATP结合盒B亚家族）转运蛋白基因-abcb 5。该基因位于斑马鱼16号染色体上，包含一个4014 bp的开放阅读框。该多肽由1337个氨基酸组成，具有人和小鼠ABCB 5/Abcb 5的大部分功能结构域和关键残基。体外功能分析表明，斑马鱼abcb 5基因的过表达可显著降低汞对LLC-PK 1细胞的毒性，提示其可能是一种潜在的汞外排转运蛋白。因此，这些发现提供了有用的见解，有助于进一步了解斑马鱼幼虫急性接触汞后的转录反应和解毒能力。(C)2016 Elsevier Inc. All rights reserved.
Mercury is a widespread toxicant in aquatic environment that can cause deleterious effects on fish. Although a number of mercury-regulated genes have been investigated in adult fish, the transcriptional responses of fish larvae to acute mercury exposure are not well understood. In this study, RNA sequencing was used to examine the transcriptional changes in developing zebrafish larvae under a low concentration of mercuric chloride exposure from 24 to 120 hpf. Our initial results showed that a total of 142.59 million raw reads were obtained from sequencing libraries and about 86% of the processed reads were mapped to the reference genome of zebrafish. Differential expression analysis identified 391 up- and 87 down-regulated genes. Gene ontology enrichment analysis revealed that most of the differential expressed genes are closely related to the regulation of cellular process, metabolic process, multicellular organismal process, biological regulation, pigmentation, and response to stimulus. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis demonstrated that antigen processing and presentation was the most significantly enriched pathway. Moreover, we characterized a novel and sensitive mercury-induced ABCB (ATP- binding cassette B subfamily) transporter gene - abcb5. This gene is localized on zebrafish chromosome 16 and contains a 4014 bp open-reading frame. The deduced polypeptide is composed of 1337 amino acids and possesses most of functional domains and critical residues defined in human and mouse ABCB5/Abcb5. Functional analysis in vitro demonstrated that overexpression of zebrafish abcb5 gene can significantly decrease the cytotoxicity of mercury in LLC-PK1 cells, implying it is a potential efflux transporter of mercury. Thus, these findings provide useful insights to help further understand the transcriptional response and detoxification ability of zebrafish larvae following acute exposure to mercury. (C) 2016 Elsevier Inc. All rights reserved.