Characterization of the Transcriptome and Gene Expression of Brain Tissue in Sevenband Grouper (Hyporthodus septemfasciatus) in Response to NNV Infection.

Jong-Oh Kim,Jae-Ok Kim,Wi-Sik Kim,Myung-Joo Oh

doi:10.3390/genes8010031

Abstract

Grouper is one of the favorite sea food resources in Southeast Asia. However, the outbreaks of the viral nervous necrosis (VNN) disease due to nervous necrosis virus (NNV) infection have caused mass mortality of grouper larvae. Many aqua-farms have suffered substantial financial loss due to the occurrence of VNN. To better understand the infection mechanism of NNV, we performed the transcriptome analysis of sevenband grouper brain tissue, the main target of NNV infection. After artificial NNV challenge, transcriptome of brain tissues of sevenband grouper was subjected to next generation sequencing (NGS) using an Illumina Hi-seq 2500 system. Both mRNAs from pooled samples of mock and NNV-infected sevenband grouper brains were sequenced. Clean reads of mock and NNV-infected samples were de novo assembled and obtained 104,348 unigenes. In addition, 628 differentially expressed genes (DEGs) in response to NNV infection were identified. This result could provide critical information not only for the identification of genes involved in NNV infection, but for the understanding of the response of sevenband groupers to NNV infection.

Highlights

Grouper is one of the highest valued marine fish and has become an important species in the aquaculture industry of various Asian countries
Brain tissues of 10 fish were randomly sampled from the aqua-farm and subjected to reverse transcription polymerase chain reaction (RT-PCR) analysis to determine betanodavirus infection according to a previous report [9]
The number of unigenes was 104,348, the total length and the average length of the Unigenes were identified after removing redundant sequences from assembled transcripts

Summary

Introduction

Grouper is one of the highest valued marine fish and has become an important species in the aquaculture industry of various Asian countries. Viral Nervous Necrosis is a serious disease in the world aquaculture industry [2,3,4]. It was reported in bigeye trevally (Caranx sexfasciatus) in the 1980s and since it has been reported in over twenty species [2,3,4]. In Korea, mass mortalities caused by VNN have been reported from various cultured marine fish such as sevenband grouper (Hyporthodus septemfasciatus), rock bream (Oplegnathus fasciatus), red drum (Sciaenops ocellatus) and olive flounder (Paralichthys olivaceus) since 1990 [5,6,7]

Methods

Results

Discussion

Conclusion