Transcriptome sequencing and de novo analysis of the northern snakehead, Ophiocephalus argus

Northern snakehead, Ophiocephalus argus Cantor, is an endemic freshwater fish in China. However, wild stocks of O. argus are dwindling sharply. Further, water conservancy projects, environmental pollution and human activities have caused the decrease of wild stocks, which has attracted much attention. Here, we have investigated the genomic information of O. argus using IlluminaHiseq 4000 sequencing. The transcriptomes of O. argus were sequenced by Illumina technology. A total of 67,564 sequences from 79,500,964 paired-end reads were generated, 33,710 unigenes were annotated based on protein databases (NCBI nonredundant (NR) databases). In total, 7182 unigenes had the clusters of orthologous group (COG) classifications, 33,710 unigenes were assigned to 59 gene ontology (GO) terms. Further, a total of 21,464 simple sequence repeats (SSRs) from 67,564 unigenes and 113,518 single nucleotide polymorphism (SNP) sites among 335 Mclean reads were yielded for O. argus based on a transcriptome-wide search. The new transcriptome data which is presented in this study for O. argus will provide valuable information for gene discovery and downstream applications, such as phylogenetic analysis, gene-expression profiling and identification of genetic markers (SSRs andSNP).