Response of microbiota and immune function to different hypotonic stress levels in giant freshwater prawn Macrobrachium rosenbergii post-larvae

Integrated analysis of a miRNA-mRNA network related to immunity and autophagy in Macrobrachium rosenbergii infected with Aeromonas hydrophila

MicroRNAs (miRNAs) are a group of RNAs that regulate gene expression in the post-transcriptionally. miRNAs can regulate numerous processes, such as the immune response, due to their dynamic expression patterns. The giant freshwater prawn Macrobrachium rosenbergii is a major freshwater aquaculture prawn that is attacked by various bacteria, including Aeromonas hydrophila. For this study, we performed an analysis of the miRNA and mRNA transcriptome analysis of M. rosenbergii which was infected with A. hydrophila. We identified 56 differentially expressed miRNAs (DEMs) and 1542 differentially expressed mRNAs. Furthermore, an integrated analysis of miRNA-mRNA expression led to the identification of 729 differentially predicted target genes (DETGs) of the DEMs. Multiple functional categories related to immunity, apoptosis, and autophagy were found to be enriched in the DETGs. During the infection of M. rosenbergii by A. hydrophila, an elaborate regulatory network involving Toll and immune deficiency (IMD) signaling, mitogen-activated protein kinase (MAPK) signaling, lysosome, and cell apoptosis was formed by a complex interplay of 40 crucial DEMs and 22 DETGs, all associated with the immune and autophagy pathway. The findings suggest that infection with A. hydrophila triggers intricate responses in both miRNA and mRNA, significantly impacting immune and autophagy processes in M. rosenbergii.

Transcriptomic Analysis in Marine Medaka Gill Reveals That the Hypo-Osmotic Stress Could Alter the Immune Response via the IL17 Signaling Pathway

Fish gills are the major osmoregulatory tissue that contact the external water environment and have developed an effective osmoregulatory mechanism to maintain cellular function. Marine medaka (Oryzias melastigma) has the ability to live in both seawater and fresh water environments. The present study performed a seawater (SW) to 50% seawater (SFW) transfer, and the gill samples were used for comparative transcriptomic analysis to study the alteration of hypo-osmotic stress on immune responsive genes in this model organism. The result identified 518 differentiated expressed genes (DEGs) after the SW to SFW transfer. Various pathways such as p53 signaling, forkhead box O signaling, and the cell cycle were enriched. Moreover, the immune system was highlighted as one of the top altered biological processes in the enrichment analysis. Various cytokines, chemokines, and inflammatory genes that participate in the IL-17 signaling pathway were suppressed after the SW to SFW transfer. On the other hand, some immunoglobulin-related genes were up-regulated. The results were further validated by real-time qPCR. Taken together, our study provides additional gill transcriptome information in marine medaka; it also supports the notion that osmotic stress could influence the immune responses in fish gills.