Metagenome of a Pennaeus vannamei shrimp infected with the White Spot Syndrome Virus
White leg Shrimp, microbiota, shotgun metagenomics, WSSV
White-leg shrimp (Penaeus vannamei) is the most widely cultivated species in
aquaculture in the world. Commercial cultivation usually occurs at high densities, which
favors the selection of virulent pathogens, causing epidemic outbreaks. Among the
pathogens that cause shingles, the virus that causes White Spot Syndrome Virus
(WSSV) is known for outbreaks that can result in more than 80% of mortality in less
than a week. As a result, the use of preventive strategies that allow the identification and
monitoring of microbiota in crops has become increasingly necessary, especially in
intensive systems. Recently, the use of metagenomics has been suggested for
monitoring in aquaculture. Several studies have used 16S metagenomics to study the
microbiota associated with healthy or infected shrimp with specific pathogens. Other
studies have addressed the metagenomic shotgun to discover new viruses. The
metagenomic shotgun is potentially more informative than the metagenomic by marker
genes, allowing the retrieval of genomic information from the host and its symbionts,
including viruses, whose composition may act as bioindicators of the disease stage. In
this study, the shotgun metagenomic was used to analyze the caudal muscle of a P.
vannamei specimen infected by WSSV. Taxonomic and functional classifications were
made to obtain the respective profiles of the metagenomic data. P. vannamei and WSSV
were the most abundant organisms in the classification by reads. In the analysis of the
contigs, greater abundance of contigs was observed for shrimp, bacteria and WSSV,
respectively. Functional classification was performed using the MEGAN software and
resulted in few representative groups of protein functions, which were not sufficient to
establish a functional profile of the sample. A taxonomic classification from the
BLASTx was also performed with the MEGAN and presented results similar to the
classification using BLASTn. The BLASTn results enabled the assembly of the
complete mitochondrial genome of P. vannamei. This study provides support for the use
of the shotgun metagenomics as a tool for the monitoring of the microbiota in shrimp
cultures, and it is possible to simultaneously retrieve information useful for population
genetics (through the mitochondrial shrimp genome) and the monitoring of symbionts
and pathogens , such as bacteria and WSSV.