S. Cortes , E. Farhat , GGM Talarico , J.A. Mennigen
{"title":"The dynamic transcriptomic response of the goldfish brain under chronic hypoxia","authors":"S. Cortes , E. Farhat , GGM Talarico , J.A. Mennigen","doi":"10.1016/j.cbd.2024.101233","DOIUrl":null,"url":null,"abstract":"<div><p>Oxygen is essential to fuel aerobic metabolism. Some species evolved mechanisms to tolerate periods of severe hypoxia and even anoxia in their environment. Among them, goldfish (<em>Carassius auratus</em>) are unique, in that they do not enter a comatose state under severely hypoxic conditions. There is thus significant interest in the field of comparative physiology to uncover the mechanistic basis underlying hypoxia tolerance in goldfish, with a particular focus on the brain. Taking advantage of the recently published and annotated goldfish genome, we profile the transcriptomic response of the goldfish brain under normoxic (21 kPa oxygen saturation) and, following gradual reduction, constant hypoxic conditions after 1 and 4 weeks (2.1 kPa oxygen saturation). In addition to analyzing differentially expressed protein-coding genes and enriched pathways, we also profile differentially expressed microRNAs (miRs). Using in silico approaches, we identify possible miR-mRNA relationships. Differentially expressed transcripts compared to normoxia were either common to both timepoints of hypoxia exposure (<em>n</em> = 174 mRNAs; <em>n</em> = 6 miRs), or exclusive to 1-week (<em>n</em> = 441 mRNAs; <em>n</em> = 23 miRs) or 4-week hypoxia exposure (<em>n</em> = 491 mRNAs; <em>n</em> = 34 miRs). Under chronic hypoxia, an increasing number of transcripts, including those of paralogous genes, was downregulated over time, suggesting a decrease in transcription. GO-terms related to the vascular system, oxidative stress, stress signalling, oxidoreductase activity, nucleotide- and intermediary metabolism, and mRNA posttranscriptional regulation were found to be enriched under chronic hypoxia. Known ‘hypoxamiRs’, such as <em>miR-210-3p/5p</em>, and miRs such as <em>miR-29b-3p</em> likely contribute to posttranscriptional regulation of these pathways under chronic hypoxia in the goldfish brain.</p></div>","PeriodicalId":55235,"journal":{"name":"Comparative Biochemistry and Physiology D-Genomics & Proteomics","volume":null,"pages":null},"PeriodicalIF":2.2000,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Comparative Biochemistry and Physiology D-Genomics & Proteomics","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1744117X24000467","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Oxygen is essential to fuel aerobic metabolism. Some species evolved mechanisms to tolerate periods of severe hypoxia and even anoxia in their environment. Among them, goldfish (Carassius auratus) are unique, in that they do not enter a comatose state under severely hypoxic conditions. There is thus significant interest in the field of comparative physiology to uncover the mechanistic basis underlying hypoxia tolerance in goldfish, with a particular focus on the brain. Taking advantage of the recently published and annotated goldfish genome, we profile the transcriptomic response of the goldfish brain under normoxic (21 kPa oxygen saturation) and, following gradual reduction, constant hypoxic conditions after 1 and 4 weeks (2.1 kPa oxygen saturation). In addition to analyzing differentially expressed protein-coding genes and enriched pathways, we also profile differentially expressed microRNAs (miRs). Using in silico approaches, we identify possible miR-mRNA relationships. Differentially expressed transcripts compared to normoxia were either common to both timepoints of hypoxia exposure (n = 174 mRNAs; n = 6 miRs), or exclusive to 1-week (n = 441 mRNAs; n = 23 miRs) or 4-week hypoxia exposure (n = 491 mRNAs; n = 34 miRs). Under chronic hypoxia, an increasing number of transcripts, including those of paralogous genes, was downregulated over time, suggesting a decrease in transcription. GO-terms related to the vascular system, oxidative stress, stress signalling, oxidoreductase activity, nucleotide- and intermediary metabolism, and mRNA posttranscriptional regulation were found to be enriched under chronic hypoxia. Known ‘hypoxamiRs’, such as miR-210-3p/5p, and miRs such as miR-29b-3p likely contribute to posttranscriptional regulation of these pathways under chronic hypoxia in the goldfish brain.
期刊介绍:
Comparative Biochemistry & Physiology (CBP) publishes papers in comparative, environmental and evolutionary physiology.
Part D: Genomics and Proteomics (CBPD), focuses on “omics” approaches to physiology, including comparative and functional genomics, metagenomics, transcriptomics, proteomics, metabolomics, and lipidomics. Most studies employ “omics” and/or system biology to test specific hypotheses about molecular and biochemical mechanisms underlying physiological responses to the environment. We encourage papers that address fundamental questions in comparative physiology and biochemistry rather than studies with a focus that is purely technical, methodological or descriptive in nature.