Integrated analysis of mRNA and microRNA transcriptome related to immunity and autophagy in shrimp hemocytes infected with Spiroplasma eriocheiris.

In recent years, the industry in charge of the cultivation of Macrobrachium nipponense (M.nipponense) has suffered significant economic losses due to an infectious pathogen called Spiroplasma eriocheiris (S.eriocheiris). There has therefore been a need to identify the key immune and autophagy genes that respond to M.nipponense's infection with S. eriocheiris to analyze its immune response mechanism and the regulation of related microRNAs (miRNAs). In this study, the mRNA and miRNA transcriptome of M.nipponense's hemocytes were analyzed at different stages of infection. This analysis employed the second and third-generation sequencing technologies. In the mRNA transcriptome, 1656 genes were expressed in healthy and susceptible M.nipponense. 892 of these were significantly up-regulated, while 764 were down-regulated. 118 genes with significant differences in autophagy, endocytosis, lysosome, Toll, IMD, and VEGF pathways were obtained from the transcriptome. In the miRNA transcriptome, 312 miRNAs (Conserved: 112, PN-type: 18, PC-type: 182) were sequenced. 74 were significantly up-regulated, and 57 were down-regulated. There were 25 miRNAs involved in regulating the Toll and IMD pathways, 41 in endocytosis, 30 in lysosome, and 12 in the VEGF pathway. An integrated analysis of immune-related miRNAs and mRNAs showed that miRNAs with significant differences (P < 0.05) such as ame-miR-29b-3p, dpu-miR-1and PC-3p-945_4074, had corresponding regulatory relationships with 118 important immune genes such as Relish, Dorsal, Caspase-3, and NF-κB. This study obtained the key immune and autophagy-related genes and corresponding regulatory miRNAs in M. nipponense's hemocytes in response to an infection by S.eriocheiris. The results can provide vital data that further reveals the defense mechanism of M.nipponense's immune system against S.eriocheiris. It can also help further comprehension and interpretation of M.nipponense's resistance mechanism to the invading S.eriocheiris, and provide molecular research information for the realization of host-directed therapies (HDT) for M.nipponense.

Integrated transcriptome analysis of immune-related mRNAs and microRNAs in Macrobrachium rosenbergii infected with Spiroplasma eriocheiris.

Macrobrachium rosenbergii (M. rosenbergii), is a major aquaculture species in China and Southeast Asia. However, infection with Spiroplasma eriocheiris (S. eriocheiris) has caused huge economic losses to the cultivation of M. rosenbergii. Currently, there are few reports on the immune response mechanism of M. rosenbergii that are infected with S. eriocheiris. To clarify the immune response mechanism of M. rosenbergii infected with S. eriocheiris, the key immune genes which respond to the infection with the pathogen and the regulation of related microRNAs (miRNAs) on them were identified. In this study, the mRNA and miRNA transcriptome of hepatopancreas of M. rosenbergii at different infection stages were analyzed using high-throughput sequencing and qRT-PCR. In the mRNA transcriptome, 27,703 and 33,402 genes were expressed in healthy and susceptible M. rosenbergii, respectively. By digital gene-expression profiling analysis, 23,929 and 24,325 genes were expressed, and 223 and 373 genes were significantly up-regulated and down-regulated, respectively. A total of 145 key genes related to Toll, IMD, JAK/STAT and MAPK were excavated from the transcriptome. In the miRNA transcriptome, 549 miRNAs (Conserved: 41, PN-type: 83, PC-type: 425) were sequenced, of which 87 were significantly up-regulated and 23 were significantly down-regulated. Among the related immune pathways, there are 259 miRNAs involved in the regulation of target genes in the Toll and IMD pathways, 231 JAK/STAT pathways and 122 MAPK pathways. qRT-PCR differential detection of immune-related miRNAs and mRNAs showed that 22 miRNAs with significant differences (P < 0.05) such as mro-miR-100, PC-mro-3p-27 and PN-mro-miR-316 had corresponding regulatory relationships with 22 important immune genes such as TLR2, TLR3, TLR4, TLR5, MyD88, Pelle and Relish in different stages after infection. In this study, the immune genes and related regulatory miRNAs of M. rosenbergii in response to S. eriocheiris infection were obtained. The results can provide basic data to further reveal the immune defense mechanism of M. rosenbergii against S. eriocheiris infection.