Abstract
High-throughput sequencing was applied to analyze the effects of toxic Microcystis aeruginosa on the silver carp Hypophthalmichthys molitrix. Silver carps were exposed to two cyanobacteria species (toxic and non-toxic) for RNA-seq and miRNA-seq analysis. RNA-seq revealed that the liver tissue contained 105,379 unigenes. Of these genes, 143 were significantly differentiated, 82 were markedly up-regulated, and 61 were remarkably down-regulated. GO term enrichment analysis indicated that 35 of the 154 enriched GO terms were significantly enriched. KEGG pathway enrichment analysis demonstrated that 17 of the 118 enriched KEGG pathways were significantly enriched. A considerable number of disease/immune-associated GO terms and significantly enriched KEGG pathways were also observed. The sequence length determined by miRNA-seq was mainly distributed in 20–23 bp and composed of 882,620 unique small RNAs, and 53% of these RNAs were annotated to miRNAs. As confirmed, 272 known miRNAs were differentially expressed, 453 novel miRNAs were predicted, 112 miRNAs were well matched with 7,623 target genes, and 203 novel miRNAs were matched with 15,453 target genes. qPCR also indicated that Steap4, Cyp7a1, CABZ01088134.1, and PPP1R3G were significantly differentially expressed and might play major roles in the toxic, detoxifying, and antitoxic mechanisms of microcystin in fish.
Highlights
With the exacerbating eutrophication of inland waters, the frequency and intensity of the outbreak of freshwater algal blooms have become increasingly serious
The toxin types and contents of the two types of M. aeruginosa were determined by high-performance liquid chromatography–mass spectrometry (HPLC-MS)
The results show that compared with that in the control group, the relative GST expression in the experimental group was markedly reduced on 6 d (P < 0.05) (Fig. 1), indicating that at the time point, GST began to play its roles in the liver tissues and react with MC
Summary
With the exacerbating eutrophication of inland waters, the frequency and intensity of the outbreak of freshwater algal blooms have become increasingly serious. Under the condition, ruptured toxic cyanobacterial cells often release algal toxins, especially microcystin (MC), which is the most common and most harmful[1,2,3,4]. Endotoxins are released and cause water quality deterioration and harmful effects on aquatic animals, plants, and human health[5, 6]. RNA-seq is based on high-throughput sequencing and applied to detecting almost all transcriptional sequences of target sepcies at a certain state. High-throughput sequencing has been gradually applied as a new technique to mine miRNA, directly reveal the expression of a differentially expressed miRNA, detect novel or species-specific miRNAs, and predict their target genes. A total of 166 conservative miRNAs and 22 novel miRNAs were detected in silver carps by high-throughput sequencing, and the loss and gain of several members of the miRNA family suggested the possible evolutionary process of miRNA replication in animals[39]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
