microRNA expression variation as a potential molecular mechanism contributing to adaptation to hydrogen sulphide
microRNA expression variation as a potential molecular mechanism contributing to adaptation to hydrogen sulphide
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DOI：
10.1111/jeb.13727
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发表时间：
2020-11-28
影响因子：
2.1
通讯作者：
Tobler, Michael
中科院分区：
文献类型：
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作者：
Kelley, Joanna L.;Desvignes, Thomas;Tobler, Michael
microRNAs （miRNAs）是基因表达的转录后调控因子，在调节机体发育和生理以应对环境胁迫方面发挥重要作用。然而，在自然研究系统中，mirna在调节对不同环境的适应中的作用在很大程度上仍未被探索。在这里，我们表征了mirna及其在墨西哥Poecilia mexicana中的表达，Poecilia mexicana是一种小型鱼类，以富含有毒硫化氢（H2S）的泉的形式生活在正常溪流和极端环境中。我们发现P. mexicana与其他硬骨鱼具有相似数量的miRNA基因。此外，我们还发现了大量成熟的mirna，这些mirna在不同栖息地的本地适应种群中表达差异，这表明mirna可能有助于墨西哥假单胞菌适应硫化物环境。通过对差异表达的miRNA-mRNA对的硅晶硅鉴定显示，在硫化物环境中，mirna下调的目标是参与硫化物解毒和细胞稳态的mrna，这是在富含硫化氢的泉水中生命所必需的途径。此外，我们发现预测上调的mirna靶点作用于线粒体（16.6%的预测注释靶点），这是H2S毒性和解毒的主要部位，可能调节线粒体功能。总之，这些自然种群之间mirna的差异调控表明，mirna可能通过促进生存所需的功能和减少受H2S影响的功能来参与H2S适应。本研究为进一步研究直接证明mirna在H2S适应中的作用奠定了基础。总的来说，这项研究为全面理解自然系统中基因表达适应性变化的调控机制提供了一个关键的基石。
microRNAs (miRNAs) are post-transcriptional regulators of gene expression and can play an important role in modulating organismal development and physiology in response to environmental stress. However, the role of miRNAs in mediating adaptation to diverse environments in natural study systems remains largely unexplored. Here, we characterized miRNAs and their expression in Poecilia mexicana, a species of small fish that inhabits both normal streams and extreme environments in the form of springs rich in toxic hydrogen sulphide (H2S). We found that P. mexicana has a similar number of miRNA genes as other teleosts. In addition, we identified a large population of mature miRNAs that were differentially expressed between locally adapted populations in contrasting habitats, indicating that miRNAs may contribute to P. mexicana adaptation to sulphidic environments. In silico identification of differentially expressed miRNA-mRNA pairs revealed, in the sulphidic environment, the downregulation of miRNAs predicted to target mRNAs involved in sulphide detoxification and cellular homeostasis, which are pathways essential for life in H2S-rich springs. In addition, we found that predicted targets of upregulated miRNAs act in the mitochondria (16.6% of predicted annotated targets), which is the main site of H2S toxicity and detoxification, possibly modulating mitochondrial function. Together, the differential regulation of miRNAs between these natural populations suggests that miRNAs may be involved in H2S adaptation by promoting functions needed for survival and reducing functions affected by H2S. This study lays the groundwork for further research to directly demonstrate the role of miRNAs in adaptation to H2S. Overall, this study provides a critical stepping-stone towards a comprehensive understanding of the regulatory mechanisms underlying the adaptive variation in gene expression in a natural system.