The Alveolate Perkinsus marinus: Biological Insights from EST Gene Discovery

摘要: Perkinsus marinus, a protozoan parasite of the eastern oyster Crassostrea virginica, has devastated natural and farmed populations along Atlantic Gulf coasts United States. It is classified as member Perkinsozoa, recently established phylum considered close to ancestor ciliates, dinoflagellates, apicomplexans, key taxon for understanding unique adaptations (e.g. parasitism) within Alveolata. Despite intense pressure, no disease-resistant oysters have been identified effective therapies developed date. To gain insight into biological basis parasite's virulence pathogenesis mechanisms, identify genes encoding potential targets intervention, we generated >31,000 5' expressed sequence tags (ESTs) derived from four trophozoite libraries two P. marinus strains. Trimming clustering yielded 7,863 sequences, some which carry spliced leader. Similarity searches revealed that 55% these had hits in protein databases, 1,729 their best hit with proteins chromalveolates (E-value ≤ 1e-5). Some sequences are similar those proven be intervention other parasites, include not only proteases, antioxidant enzymes, heat shock proteins, but also associated relict plastids, such acetyl-CoA carboxylase methyl erythrithol phosphate pathway components, involved glycan assembly, folding/secretion, parasite-host interactions. Our transcriptome analysis first any contributes new its biology taxonomic position. provides very informative, albeit preliminary, glimpse expression functionally relevant chemotherapy, evidence presence plastid. Further, although display significant similarity both apicomplexans trans-spliced transcripts confirms previously affinities latter. The EST reported herein, together completed genome development transfection methodology, should result improved strategies against dermo disease.