A comparative transcriptome approach for identification of molecular changes in Aphanomyces invadans infected Channa striatus
Snakehead murrel, Channa striatus is an economically important aquatic species in Asia and are widely cultured and captured because of its nutritious and medicinal values. Their growth is predominantly affected by epizootic ulcerative syndrome (EUS) which is primarily caused by an oomycete fungus, Aphanomyces invadans. However, the molecular mechanism of immune response in murrel against this infection is still not clear. In this study, transcriptome technique was used to understand the molecular changes involved in C. striatus during A. invadans infection. RNA from the control (CF) and infected fish (IF) groups were sequenced using Illumina Hi-seq sequencing technology. For control group, 28,952,608 clean reads were generated and de novo assembly was performed to produce 60,753 contigs. For fungus infected group, 25,470,920 clean reads were obtained and assembled to produce 58,654 contigs. Differential gene expression analysis revealed that a total of 146 genes were up-regulated and 486 genes were down regulated. Most of the differentially expressed genes were involved in innate immune mechanism such as pathogen recognition, signalling and antimicrobial mechanisms. Interestingly, few adaptive immune genes, especially immunoglobulins were also significantly up regulated during fungal infection. Also, the results were validated by qRT-PCR analysis. These results indicated the involvement of various immune genes involved in both innate and adaptive immune mechanism during fungal infection in C. striatus which provide new insights into murrel immune mechanisms against A. invadans.
KeywordsSnakehead Murrel Aphanomyces invadans Epizootic ulcerative syndrome Transcriptome Gene expression
Epizootic ulcerative syndrome
World Organisation for Animal Health
Red spot disease
Next generation sequencing
Fragments per kilobase of exon per million fragments mapped
Quantitative real-time polymerase chain reaction
Pattern recognition receptors
Pathogen-associated molecular patterns
Peptidoglycan recognition proteins
Nonspecific cytotoxic cells
- PGC 1α
Peroxisome proliferator-activated receptor gamma co-activator 1 alpha
- CPT I
Carnitine palmitoyl transferase I
Leukocyte immune-type receptor
This research is supported by Department of Biotechnology (DBT), Ministry of Science and Technology, Government of India, New Delhi under the program of Aquaculture and Marine Biotechnology (No. BT/PR13183/AAQ/3/723/2015). The authors also grateful to the Deanship of Scientific Research, King Saud University for partial funding through Vice Deanship of Scientific Research Chairs. Moreover, the corresponding author would like to acknowledge Institute of Bioscience, Universiti Putra Malaysia, Malaysia for providing him visiting professor Award (UPM/PEND/500-3/4/10) to complete this study under the HICoE and SATREPS-COSMOS programs, Ministry of Higher Education Malaysia.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Research involving human and animal participants
This experiment does not contain any human participants. The animal, striped murrel Channa striatus used in this experiment was treated with care following the ethical procedures of the SRM Institute of Science and Technology (SRMIST) guidelines and regulations. All the experimental protocols were approved by the research committee of SRMIST.
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