Transcriptome Analysis of the Innate Immunity-Related Complement System in Spleen Tissue of Ctenopharyngodon idella Infected with Aeromonas hydrophila

Abstract

The grass carp (Ctenopharyngodon idella) is an important commercial farmed herbivorous fish species in China, but is susceptible to Aeromonas hydrophila infections. In the present study, we performed de novo RNA-Seq sequencing of spleen tissue from specimens of a disease-resistant family, which were given intra-peritoneal injections containing PBS with or without a dose of A. hydrophila. The fish were sampled from the control group at 0 h, and from the experimental group at 4, 8, 12, 24, 48 and 72 h. 122.18 million clean reads were obtained from the normalized cDNA libraries; these were assembled into 425,260 contigs and then 191,795 transcripts. Of those, 52,668 transcripts were annotated with the NCBI Nr database, and 41,347 of the annotated transcripts were assigned into 90 functional groups. 20,569 unigenes were classified into six main categories, including 38 secondary KEGG pathways. 2,992 unigenes were used in the analysis of differentially expressed genes (DEGs). 89 of the putative DEGs were related to the immune system and 41 of them were involved in the complement and coagulation cascades pathway. This study provides insights into the complement and complement-related pathways involved in innate immunity, through expression profile analysis of the genomic resources in C. idella. We conclude that complement and complement-related genes play important roles during defense against A. hydrophila infection. The immune response is activated at 4 h after the bacterial injections, indicating that the complement pathways are activated at the early stage of bacterial infection. The study has improved our understanding of the immune response mechanisms in C. idella to bacterial pathogens.

Transcriptomics Sequencing Provides Insights into Understanding the Mechanism of Grass Carp Reovirus Infection

“…At present, previous studies on grass carp transcriptome profiles in response to grass carp reovirus infection have been carried out [ 10 , 11 , 12 , 13 , 14 ]. Most of them involved in the discovery of immune-related genes or uncovered the antiviral immunity mechanism of grass carp.…”

“…Grass carp haemorrhage disease outbreaks are frequent and result in huge economic losses in the aquaculture industry, hence the GCRV is of particular interest to geneticists aiming to develop strategies for breeding disease-resistant fish. Recent studies on GCRV have mainly focused on identification of genes involved in immune responses to GCRV infection [ 4 , 5 ], cloning and characterization of GCRV-encoded proteins [ 6 , 7 ], the development of vaccines against GCRV [ 8 , 9 ], and transcriptomic sequencing of discovered immune-related genes or uncovered the antiviral immunity mechanism of grass carp infected with GCRV [ 10 , 11 , 12 , 13 , 14 ]. However, the mechanisms of grass carp reovirus invasion and infection remain poorly explored.…”

A transcriptome analysis focusing on inflammation-related genes of grass carp intestines following infection with Aeromonas hydrophila

“…In an effort to further understand the mechanism of A. hydrophila -induced intestinal inflammation, in this study, we generated transcriptomic data based on the grass carp model mentioned above. In contrast to other studies that focused on the transcriptomes of the grass carp head kidney, hepatopancreas, and spleen2122363940, the transcriptomic profiles of the intestines from A. hydrophila -infected and mock-infected grass carp were compared in this study. Our work also differs from that reported in Vibrio harveyi -infected carnivorous Asian seabass41.…”

“…Recently, a number of studies have generated abundant transcriptome data from blue catfish ( Ictalurus furcatus )19, blunt snout bream ( Megalobrama amblycephala )20, grass carp2122, and rohu ( Labeo rohita )23 after being infected with A. hydrophila . These studies have primarily focused on identifying immune-related genes and substantially improved our understanding of the host immune defense mechanisms against bacterial infection.…”

Toward a Reference Gene Catalog of Human Primary Monocytes

“…RNA-Seq is able to qualitatively and quantitatively explore any RNA type, including messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and small interfering RNAs (siRNAs), as well as novel transcripts (Dong and Chen, 2013). Recent studies have applied RNA-Seq technology for transcriptome profiling of several tissues and cell types such as endometrium (Zieba et al, 2015), spleen (Dang et al, 2016), T cells (Mitchell et al, 2015), B cells (Toung et al, 2011), and macrophages (Beyer et al, 2012).…”