Catherine M Ronning¹ , Arun K Dhar¹

¹  Advanced BioNutrition Corp., 7155 Columbia Gateway Drive, Columbia, MD, 21046, USA

²  Approved for public release, distribution unlimited

White spot syndrome virus (WSSV), causal agent of white spot syndrome disease, incurs devastating losses to shrimp aquaculture worldwide. Differential gene expression analysis was performed on expressed sequence tags (ESTs) derived from hepatopancreatic tissue of healthy and WSSV-infected P. stylirostris. A total of 934 high-quality sequences were obtained, which upon assembly collapsed into 664 unigenes, 55.3% of which were specific to the healthy library and 39.9% to the WSSV library. Putative annotations were assigned to 273 unigenes, leaving 391 unidentified, potentially novel shrimp genes. Hemocyanin was the most abundant gene identified in both libraries; however, twelve of the 20 high-copy-number unigenes had no significant similarity to any GenBank protein. Additionally, putative hemocyanin, ribosomal protein, proteasomal protein, and cortical rod protein-2 genes were found to be overabundant in the healthy library, while chitinase, C-type lectin, zinc proteinase, and carboxypeptidase were overabundant in the WSSV-infected library. To further delineate differences in gene expression between the two libraries, Gene Ontology (GO) terms were assigned. The WSSV-infected library contained an overabundance of genes involved in catalytic and molecular transducer activities, and more genes involved in multicellular organismal, response to stimulus, and immune system biological processes relative to the healthy library. Preliminary codon usage analysis of this collection of P. stylirostris ESTs indicates a preference towards certain codons in genes specific to the WSSV-infected library. A comprehensive codon usage analysis comparing all publicly available shrimp ESTs with ESTs of several other animal species, including Spodoptera frugiperda, Drosophila melanogaster, and Homo sapiens, is currently underway.