@article {49634, title = {The ingi and RIME non-LTR retrotransposons are not randomly distributed in the genome of Trypanosoma brucei.}, journal = {Mol Biol Evol}, volume = {21}, year = {2004}, month = {2004 Mar}, pages = {520-8}, abstract = {

The ingi (long and autonomous) and RIME (short and nonautonomous) non--long-terminal repeat retrotransposons are the most abundant mobile elements characterized to date in the genome of the African trypanosome Trypanosoma brucei. These retrotransposons were thought to be randomly distributed, but a detailed and comprehensive analysis of their genomic distribution had not been performed until now. To address this question, we analyzed the ingi/RIME sequences and flanking sequences from the ongoing T. brucei genome sequencing project (TREU927/4 strain). Among the 81 ingi/RIME elements analyzed, 60\% are complete, and 7\% of the ingi elements (approximately 15 copies per haploid genome) appear to encode for their own transposition. The size of the direct repeat flanking the ingi/RIME retrotransposons is conserved (i.e., 12-bp), and a strong 11-bp consensus pattern precedes the 5{\textquoteright}-direct repeat. The presence of a consensus pattern upstream of the retroelements was confirmed by the analysis of the base occurrence in 294 GSS containing 5{\textquoteright}-adjacent ingi/RIME sequences. The conserved sequence is present upstream of ingis and RIMEs, suggesting that ingi-encoded enzymatic activities are used for retrotransposition of RIMEs, which are short nonautonomous retroelements. In conclusion, the ingi and RIME retroelements are not randomly distributed in the genome of T. brucei and are preceded by a conserved sequence, which may be the recognition site of the ingi-encoded endonuclease.

}, keywords = {Amino Acid Sequence, Animals, Base Sequence, Consensus Sequence, Genome, Protozoan, Molecular Sequence Data, Retroelements, Sequence Analysis, Trypanosoma brucei brucei}, issn = {0737-4038}, doi = {10.1093/molbev/msh045}, author = {Bringaud, Frederic and Biteau, Nicolas and Zuiderwijk, Eduard and Berriman, Matthew and El-Sayed, Najib M and Ghedin, Elodie and Melville, Sara E and Hall, Neil and Baltz, Th{\'e}o} } @article {49683, title = {Reducing storage requirements for biological sequence comparison.}, journal = {Bioinformatics}, volume = {20}, year = {2004}, month = {2004 Dec 12}, pages = {3363-9}, abstract = {

MOTIVATION: Comparison of nucleic acid and protein sequences is a fundamental tool of modern bioinformatics. A dominant method of such string matching is the {\textquoteright}seed-and-extend{\textquoteright} approach, in which occurrences of short subsequences called {\textquoteright}seeds{\textquoteright} are used to search for potentially longer matches in a large database of sequences. Each such potential match is then checked to see if it extends beyond the seed. To be effective, the seed-and-extend approach needs to catalogue seeds from virtually every substring in the database of search strings. Projects such as mammalian genome assemblies and large-scale protein matching, however, have such large sequence databases that the resulting list of seeds cannot be stored in RAM on a single computer. This significantly slows the matching process.

RESULTS: We present a simple and elegant method in which only a small fraction of seeds, called {\textquoteright}minimizers{\textquoteright}, needs to be stored. Using minimizers can speed up string-matching computations by a large factor while missing only a small fraction of the matches found using all seeds.

}, keywords = {algorithms, Databases, Genetic, Information Storage and Retrieval, Numerical Analysis, Computer-Assisted, sequence alignment, Sequence Analysis}, issn = {1367-4803}, doi = {10.1093/bioinformatics/bth408}, author = {Roberts, Michael and Hayes, Wayne and Hunt, Brian R and Mount, Stephen M and Yorke, James A} }