Large yellow croaker (Larimichthys crocea) is an economically important fish, with the annual production ranking second among maricultured fish in China. Outbreaks of visceral white nodules disease caused by Pseudomonas plecoglossicida have led to substantial economic losses for the L. crocea aquaculture industry. However, L. crocea defense strategies against P. plecoglossicida infection, especially the role of microRNAs (miRNAs) in the defense against P. plecoglossicida, are poorly understood. Here, we analyzed changes in the mRNA and miRNA expression profiles in the spleen of L. crocea at 96 h post-infection and explored its defensive strategies. Principal component analysis (PCA) showed that P. plecoglossicida infection brought about a profound remodeling of both the miRNA and mRNA profiles. Enrichment analysis showed that the inflammatory response (IL-17 signaling pathway, chemokines and chemokine receptor pathway), ATP synthesis (TCA cycle and oxidative phosphorylation), apoptosis and necroptosis (TNF signaling pathway), and proteolysis (proteasome pathway) were enriched and upregulated by P. plecoglossicida. Thus, P. plecoglossicida infection activated the inflammatory response, stimulated ATP synthesis, and accelerated apoptosis and necroptosis, and promoted proteasome-mediated protein degradation. Additionally, integrated analysis identified 568 miRNA-mRNA pairs. KEGG enrichment analysis of the miRNA targets showed that the enriched pathways included cytokine-cytokine receptor interaction, the chemokine signaling pathway, the C-type lectin receptor signaling pathway, and apoptosis. Integrated analysis identified 14 miRNAs which targeted 44 immune-related genes. Altogether, our results revealed not only the role of the inflammatory response, energy metabolism, apoptosis and necroptosis, and the proteasome pathway in L. crocea defense against P. plecoglossicida infection, but also the regulatory networks of miRNAs associated with host defense against P. plecoglossicida.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |