Comparative transcriptome analysis of red swamp crayfish (Procambarus clarkia) hepatopancreas in response to WSSV and Aeromonas hydrophila infection

Abstract

To better study the immune system of shrimp and understand the similarities and differences between the host's immune defense against viral and bacterial infections, this study used a comparative transcriptomics method to systematically analyze the hepatopancreas of the crayfish Procambarus clarkia in response to WSSV and A. hydrophila infection. After assembly, there was an average of 24,404,837 clean reads were obtained after filtering out low-quality reads. Unigenes were annotated by comparing against nr, Swiss-Prot\KEGG\COG\KOG\GO and Pfam databases, and 17,954 unigenes were annotated in at least one database. 2600 and 2073 differentially expressed genes (DEGs) in the hepatopancreas in response to WSSV and A. hydrophila infections were identified respectively. The GO and KEGG enrichment analyses of DEGs were conducted to further explore their functions. The pathways like PI3K-Akt signaling pathway, mTOR signaling pathway, Jak-STAT signaling pathway, NF-κB signaling pathway, VEGF signaling pathway, Ras signaling pathway, were the most prominent for immunity-related DEGs in C-/W-Groups, while Endocytosis, Lysozyme, Focal adhesion, Phagosome, Peroxisome, MAPK signaling pathway were observed in C-/A-Groups. Furthermore, the expression levels of nine selected immune-related DEGs were validated by qRT-PCR, substantiating the reliability of RNA-Seq results. This study not only provides effective data support to reveal the different immune defense strategies by P. clarkia to cope with bacterial and WSSV infections, but also to provide new information about the immune system and defense mechanisms of shrimp.

Keywords: Aeromonas hydrophila; Hepatopancreas; Procambarus clarkia; Transcriptome; WSSV.