@article {49648, title = {The Alveolate Perkinsus marinus: biological insights from EST gene discovery.}, journal = {BMC Genomics}, volume = {11}, year = {2010}, month = {2010}, pages = {228}, abstract = {

BACKGROUND: Perkinsus marinus, a protozoan parasite of the eastern oyster Crassostrea virginica, has devastated natural and farmed oyster populations along the Atlantic and Gulf coasts of the United States. It is classified as a member of the Perkinsozoa, a recently established phylum considered close to the ancestor of ciliates, dinoflagellates, and apicomplexans, and a key taxon for understanding unique adaptations (e.g. parasitism) within the Alveolata. Despite intense parasite pressure, no disease-resistant oysters have been identified and no effective therapies have been developed to date.

RESULTS: To gain insight into the biological basis of the parasite{\textquoteright}s virulence and pathogenesis mechanisms, and to identify genes encoding potential targets for intervention, we generated>31,000 5{\textquoteright} expressed sequence tags (ESTs) derived from four trophozoite libraries generated from two P. marinus strains. Trimming and clustering of the sequence tags yielded 7,863 unique sequences, some of which carry a spliced leader. Similarity searches revealed that 55\% of these had hits in protein sequence databases, of which 1,729 had their best hit with proteins from the chromalveolates (E-value

CONCLUSIONS: Our transcriptome analysis of P. marinus, the first for any member of the Perkinsozoa, contributes new insight into its biology and taxonomic position. It provides a very informative, albeit preliminary, glimpse into the expression of genes encoding functionally relevant proteins as potential targets for chemotherapy, and evidence for the presence of a relict plastid. Further, although P. marinus sequences display significant similarity to those from both apicomplexans and dinoflagellates, the presence of trans-spliced transcripts confirms the previously established affinities with the latter. The EST analysis reported herein, together with the recently completed sequence of the P. marinus genome and the development of transfection methodology, should result in improved intervention strategies against dermo disease.

}, keywords = {Alveolata, Animals, Expressed Sequence Tags, Ostreidae, Phylogeny}, issn = {1471-2164}, doi = {10.1186/1471-2164-11-228}, author = {Joseph, Sandeep J and Fern{\'a}ndez-Robledo, Jos{\'e} A and Gardner, Malcolm J and El-Sayed, Najib M and Kuo, Chih-Horng and Schott, Eric J and Wang, Haiming and Kissinger, Jessica C and Vasta, Gerardo R} } @article {49641, title = {Analysis of fat body transcriptome from the adult tsetse fly, Glossina morsitans morsitans.}, journal = {Insect Mol Biol}, volume = {15}, year = {2006}, month = {2006 Aug}, pages = {411-24}, abstract = {

Tsetse flies (Diptera: Glossinidia) are vectors of pathogenic African trypanosomes. To develop a foundation for tsetse physiology, a normalized expressed sequence tag (EST) library was constructed from fat body tissue of immune-stimulated Glossina morsitans morsitans. Analysis of 20,257 high-quality ESTs yielded 6372 unique genes comprised of 3059 tentative consensus (TC) sequences and 3313 singletons (available at http://aksoylab.yale.edu). We analysed the putative fat body transcriptome based on homology to other gene products with known functions available in the public domain. In particular, we describe the immune-related products, reproductive function related yolk proteins and milk-gland protein, iron metabolism regulating ferritins and transferrin, and tsetse{\textquoteright}s major energy source proline biosynthesis. Expression analysis of the three yolk proteins indicates that all are detected in females, while only the yolk protein with similarity to lipases, is expressed in males. Milk gland protein, apparently important for larval nutrition, however, is primarily synthesized by accessory milk gland tissue.

}, keywords = {Adipose Tissue, Animals, Base Sequence, Computational Biology, DNA Primers, Egg Proteins, Expressed Sequence Tags, Female, Gene Expression Profiling, Insect Vectors, Male, Molecular Sequence Data, Reverse Transcriptase Polymerase Chain Reaction, Sequence Analysis, DNA, Sex Factors, Tsetse Flies}, issn = {0962-1075}, doi = {10.1111/j.1365-2583.2006.00649.x}, author = {Attardo, G M and Strickler-Dinglasan, P and Perkin, S A H and Caler, E and Bonaldo, M F and Soares, M B and El-Sayeed, N and Aksoy, S} } @article {49682, title = {Comprehensive analysis of alternative splicing in rice and comparative analyses with Arabidopsis.}, journal = {BMC Genomics}, volume = {7}, year = {2006}, month = {2006}, pages = {327}, abstract = {

BACKGROUND: Recently, genomic sequencing efforts were finished for Oryza sativa (cultivated rice) and Arabidopsis thaliana (Arabidopsis). Additionally, these two plant species have extensive cDNA and expressed sequence tag (EST) libraries. We employed the Program to Assemble Spliced Alignments (PASA) to identify and analyze alternatively spliced isoforms in both species.

RESULTS: A comprehensive analysis of alternative splicing was performed in rice that started with >1.1 million publicly available spliced ESTs and over 30,000 full length cDNAs in conjunction with the newly enhanced PASA software. A parallel analysis was performed with Arabidopsis to compare and ascertain potential differences between monocots and dicots. Alternative splicing is a widespread phenomenon (observed in greater than 30\% of the loci with transcript support) and we have described nine alternative splicing variations. While alternative splicing has the potential to create many RNA isoforms from a single locus, the majority of loci generate only two or three isoforms and transcript support indicates that these isoforms are generally not rare events. For the alternate donor (AD) and acceptor (AA) classes, the distance between the splice sites for the majority of events was found to be less than 50 basepairs (bp). In both species, the most frequent distance between AA is 3 bp, consistent with reports in mammalian systems. Conversely, the most frequent distance between AD is 4 bp in both plant species, as previously observed in mouse. Most alternative splicing variations are localized to the protein coding sequence and are predicted to significantly alter the coding sequence.

CONCLUSION: Alternative splicing is widespread in both rice and Arabidopsis and these species share many common features. Interestingly, alternative splicing may play a role beyond creating novel combinations of transcripts that expand the proteome. Many isoforms will presumably have negative consequences for protein structure and function, suggesting that their biological role involves post-transcriptional regulation of gene expression.

}, keywords = {Alternative Splicing, Arabidopsis, DNA, Complementary, Expressed Sequence Tags, Oryza}, issn = {1471-2164}, doi = {10.1186/1471-2164-7-327}, author = {Campbell, Matthew A and Haas, Brian J and Hamilton, John P and Mount, Stephen M and Buell, C Robin} } @article {49685, title = {Improving the Arabidopsis genome annotation using maximal transcript alignment assemblies.}, journal = {Nucleic Acids Res}, volume = {31}, year = {2003}, month = {2003 Oct 1}, pages = {5654-66}, abstract = {

The spliced alignment of expressed sequence data to genomic sequence has proven a key tool in the comprehensive annotation of genes in eukaryotic genomes. A novel algorithm was developed to assemble clusters of overlapping transcript alignments (ESTs and full-length cDNAs) into maximal alignment assemblies, thereby comprehensively incorporating all available transcript data and capturing subtle splicing variations. Complete and partial gene structures identified by this method were used to improve The Institute for Genomic Research Arabidopsis genome annotation (TIGR release v.4.0). The alignment assemblies permitted the automated modeling of several novel genes and >1000 alternative splicing variations as well as updates (including UTR annotations) to nearly half of the approximately 27 000 annotated protein coding genes. The algorithm of the Program to Assemble Spliced Alignments (PASA) tool is described, as well as the results of automated updates to Arabidopsis gene annotations.

}, keywords = {algorithms, Alternative Splicing, Arabidopsis, DNA, Complementary, Expressed Sequence Tags, Genome, Plant, Introns, Plant Proteins, RNA, Plant, sequence alignment, software, Transcription, Genetic, Untranslated Regions}, issn = {1362-4962}, author = {Haas, Brian J and Delcher, Arthur L and Mount, Stephen M and Wortman, Jennifer R and Smith, Roger K and Hannick, Linda I and Maiti, Rama and Ronning, Catherine M and Rusch, Douglas B and Town, Christopher D and Salzberg, Steven L and White, Owen} }