ShrimpGPAT: a gene and protein annotation tool for knowledge sharing and gene discovery in shrimp.

BACKGROUND: Although captured and cultivated marine shrimp constitute highly important seafood in terms of both economic value and production quantity, biologists have little knowledge of the shrimp genome and this partly hinders their ability to improve shrimp aquaculture. To help improve this situation, the Shrimp Gene and Protein Annotation Tool (ShrimpGPAT) was conceived as a community-based annotation platform for the acquisition and updating of full-length complementary DNAs (cDNAs), Expressed Sequence Tags (ESTs), transcript contigs and protein sequences of penaeid shrimp and their decapod relatives and for in-silico functional annotation and sequence analysis. DESCRIPTION: ShrimpGPAT currently holds quality-filtered, molecular sequences of 14 decapod species (~500,000 records for six penaeid shrimp and eight other decapods). The database predominantly comprises transcript sequences derived by both traditional EST Sanger sequencing and more recently by massive-parallel sequencing technologies. The analysis pipeline provides putative functions in terms of sequence homologs, gene ontologies and protein-protein interactions. Data retrieval can be conducted easily either by a keyword text search or by a sequence query via BLAST, and users can save records of interest for later investigation using tools such as multiple sequence alignment and BLAST searches against pre-defined databases. In addition, ShrimpGPAT provides space for community insights by allowing functional annotation with tags and comments on sequences. Community-contributed information will allow for continuous database enrichment, for improvement of functions and for other aspects of sequence analysis. CONCLUSIONS: ShrimpGPAT is a new, free and easily accessed service for the shrimp research community that provides a comprehensive and up-to-date database of quality-filtered decapod gene and protein sequences together with putative functional prediction and sequence analysis tools. An important feature is its community-based functional annotation capability that allows the research community to contribute knowledge and insights about the properties of molecular sequences for better, shared, functional characterization of shrimp genes. Regularly updated and expanded with data on more decapods, ShrimpGPAT is publicly available at http://shrimpgpat.sc.mahidol.ac.th/.

Complete genome sequence of virulence-enhancing Siphophage VHS1 from Vibrio harveyi.

Vibrio harveyi siphophage 1 (VHS1) is a tailed phage with an icosahedral head of approximately 66 nm in diameter and an unornamented, flexible tail of approximately 153 nm in length. When Vibrio harveyi 1114GL is lysogenized with VHS1, its virulence for the black tiger shrimp (Penaeus monodon) increases by more than 100 times, and this coincides with production of a toxin(s) associated with shrimp hemocyte agglutination. Curiously, the lysogen does not show increased virulence for the whiteleg shrimp (Penaeus [Litopenaeus] vannamei). Here we present and annotate the complete, circular genome of VHS1 (81,509 kbp; GenBank accession number JF713456). By software analysis, the genome contains 125 putative open reading frames (ORFs), all of which appear to be located on the same DNA strand, similar to the case for many other bacteriophages. Most of the putative ORFs show no significant homology to known sequences in GenBank. Notable exceptions are ORFs for a putative DNA polymerase and putative phage structural proteins, including a portal protein, a phage tail tape measure protein, and a phage head protein. The last protein was identified as a component of the species-specific toxin mixture described above as being associated with agglutination of hemocytes from P. monodon.

Predicted sub-populations in a marine shrimp proteome as revealed by combined EST and cDNA data from multiple Penaeus species.

BACKGROUND: Many species of marine shrimp in the Family Penaeidae, viz. Penaeus (Litopenaeus) vannamei, Penaeus monodon, Penaeus (Fenneropenaeus) chinensis, and Penaeus (Marsupenaeus) japonicus, are animals of economic importance in the aquaculture industry. Yet information about their DNA and protein sequences is lacking. In order to predict their collective proteome, we combined over 270,000 available EST and cDNA sequences from the 4 shrimp species with all protein sequences of Drosophila melanogaster and Caenorhabditis elegans. EST data from 4 other crustaceans, the crab Carcinus maenas, the lobster Homarus americanus (Decapoda), the water flea Daphnia pulex, and the brine shrimp Artemia franciscana were also used. FINDINGS: Similarity searches from EST collections of the 4 shrimp species matched 64% of the protein sequences of the fruit fly, but only 45% of nematode proteins, indicating that the shrimp proteome content is more similar to that of an insect than a nematode. Combined results with 4 additional non-shrimp crustaceans increased matching to 78% of fruit fly and 56% of nematode proteins, suggesting that present shrimp EST collections still lack sequences for many conserved crustacean proteins. Analysis of matching data revealed the presence of 4 EST groups from shrimp, namely sequences for proteins that are both fruit fly-like and nematode-like, fruit fly-like only, nematode-like only, and non-matching. Gene ontology profiles of proteins for the 3 matching EST groups were analyzed. For non-matching ESTs, a small fraction matched protein sequences from other species in the UniProt database, including other crustacean-specific proteins. CONCLUSIONS: Shrimp ESTs indicated that the shrimp proteome is comprised of sub-populations of proteins similar to those common to both insect and nematode models, those present specifically in either model, or neither. Combining small EST collections from related species to compensate for their small size allowed prediction of conserved expressed protein components encoded by their uncharacterized genomes. The organized data should be useful for transferring annotation data from model species into shrimp data and for further studies on shrimp proteins with particular functions or groups.

Expression of biologically active crustacean hyperglycemic hormone (CHH) of Penaeus monodon in Pichia pastoris.

Crustacean hyperglycemic hormone (CHH), molt-inhibiting hormone (MIH), and gonad-inhibiting hormone (GIH) are members of a major peptide family produced from the X-organ sinus gland complex in the eyestalk of crustaceans. This peptide family plays important roles in controlling several physiologic processes such as regulation of growth and reproduction. In this study the complementary DNA encoding a peptide related to the CHH/MIH/GIH family (so-called Pem-CMG) of the black tiger prawn Penaeus monodon was successfully expressed in the yeast Pichia pastoris under the control of the AOX1 promoter. The recombinant Pem-CMG was secreted into the culture medium using the alpha-factor signal sequence; of Saccharomyces cerevisiae without the Glu-Ala-Glu-Ala spacer peptide. The amino terminus of the recombinant Pem-CMG was correctly processed as evidenced by amino-terminal peptide sequencing. The recombinant Pem-CMG was purified by reverse-phase high-performance liquid chromotography and used in a biological assay for CHH activity. The final yield of the recombinant Pem-CMG after purification was 260 micro g/L of the culture medium. Both crude and purified recombinant Pem-CMG produced from P. pastoris showed the ability to elevate the glucose level in the hemolymph of eyestalk-ablated P. monodon, which demonstrates that Pem-CMG peptide functions as hyperglycemic hormone in P. monodon.