Detection of viruses in abalone tissue using metagenomics technology

Abstract

Abalone (Haliotis diversicolor) is an important marine and mariculture food resource that has been severely affected by several viral disease outbreaks in recent years, and the virus causing the disease has not been unequivocally identified. To establish viral metagenomic research protocols for H. diversicolor, we applied differential centrifugation and sucrose gradient ultracentrifugation to obtain virus-like particles from crude tissue extracts. After nuclease treatment to remove host nucleic acid, reverse transcription, and double-stranded amplification, we used the HiSeq 2500 platform to generate a viral genome dataset. A total of 6,055,591,750 nucleotides were produced from 24,222,367 reads, generating 65,382 contigs, with a total sequence length of 14,239,389 bp. We analysed and evaluated the sequence data by quality control mapping, among other methods and the results indicated good quality data. Alignment of the data with sequences in the GenBank virus database identified homology with a large number of Abalone Herpes-like Virus (AbHV) and Shriveling Syndrome-associated Virus (AbSV) sequences, and also a certain amount of White Spot Syndrome Virus (WSSV) sequences.