Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
Sci Total Environ. 2019 Apr 15;661:226-234. doi: 10.1016/j.scitotenv.2019.01.156. Epub 2019 Jan 15.
Many studies have reported that behavior and bioluminescence of fireflies could be affected by changes in environment conditions. However, little is known about how the deterioration of the aquatic environment affects aquatic fireflies, particularly with respect to molecular responses following exposure to water pollutants, such as benzo(a)pyrene (BaP), which is a key indicator in environmental risk assessment because of the hazards it poses. Here, whole transcriptome sequencing and gene expression analysis were performed on freshwater fireflies (Luciola leii) exposed to BaP (concentration of 0.01 mg/L). Four transcriptomic libraries were constructed for the control and treatment groups, including two biological replicates. From the mixed pools (each pool contains 60 individuals from three time points), a total of 54,282 unigenes were assembled. Furthermore, 329,337 of Single-nucleotide Polymorphisms (SNPs) and 1324 of Simple Sequence Repeats (SSRs) were predicted using bioinformatics, which is useful for the future development of molecular markers. Subsequently, 2414 differently expressed genes (DEGs) were identified in response to BaP stress in comparison to the control, including 1350 up-regulated and 1064 down-regulated DEGs. Functional enrichment showed that these DEGs are primarily related to innate immunity; xenobiotic biodegradation and response, biomacromolecule metabolism, biosynthesis, and absorption. Eight key BaP-responsive DEGs were screened to survey the dynamic changes of expression in response to BaP stress at different time points, and to validate the RNA sequencing data using quantitative real-time PCR. The results indicate that the expression of genes encoding UGT, CYP3A, CYP9, CYP6AS5 and ADHP were induced, while those encoding UGT2B10L, PTGDS, and ALDH were reduced, to participate in response to the BaP exposure and potentially help counteract the adverse effects of BaP. This investigation provides insight into the toxicological response of fireflies to the occurrence of water deterioration.
许多研究表明，萤火虫的行为和生物发光可能会受到环境条件变化的影响。然而，对于水生萤火虫如何受到水生环境恶化的影响，我们知之甚少，特别是对于暴露于水中污染物（如苯并[a]芘（BaP））后分子反应的了解甚少，BaP 是环境风险评估中的一个关键指标，因为它具有危害性。在这里，我们对暴露于 BaP（浓度为 0.01mg/L）的淡水萤火虫（Luciola leii）进行了全转录组测序和基因表达分析。为对照组和处理组构建了四个转录组文库，包括两个生物学重复。从混合池中（每个池包含来自三个时间点的 60 个个体），共组装了 54282 个非编码基因。此外，通过生物信息学预测了 329337 个单核苷酸多态性（SNP）和 1324 个简单序列重复（SSR），这对于未来的分子标记开发很有用。随后，与对照组相比，在 BaP 应激下鉴定出 2414 个差异表达基因（DEGs），包括 1350 个上调和 1064 个下调的 DEGs。功能富集表明，这些 DEGs主要与先天免疫、外来生物生物降解和反应、生物大分子代谢、生物合成和吸收有关。筛选了 8 个关键的 BaP 响应 DEGs，以调查不同时间点 BaP 应激下表达的动态变化，并使用定量实时 PCR 验证 RNA 测序数据。结果表明，编码 UGT、CYP3A、CYP9、CYP6AS5 和 ADHP 的基因表达被诱导，而编码 UGT2B10L、PTGDS 和 ALDH 的基因表达被降低，以参与 BaP 暴露的反应，并可能有助于抵消 BaP 的不利影响。这项研究深入了解了萤火虫对水质恶化发生的毒理学反应。
