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A Fast Hybrid Short Read Fragment Assembly Algorithm. Introduction. Second-generation DNA technologies Traditional : Sanger shotgun techniques New techniques(2007 & 2008): SSAKE, UCAKE and SHARCGS --based on greedy extension Edena, Velvet, Euler-SR --based on graph. Taipan Method: Two steps.
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Introduction • Second-generation DNA technologies • Traditional : Sanger shotgun techniques • New techniques(2007 & 2008): • SSAKE, UCAKE and SHARCGS--based on greedy extension • Edena, Velvet, Euler-SR--based on graph
Taipan Method: Two steps • 1. Greedy Extension • iteratively extended by one base at a time both in 3’ direction and 5’ direction • 2. Graph-based Method • to assembly the constructed contig from previous step.
Example • Usage: taipan -f {inputfilename} -k {minimal_overlap} [-t {threshold}] [-o {seed_occ}] [-v {verbose}] [-c {min_contig_length}] • Result:
Optimal spliced alignments of short sequence reads Fabio De Bona Bioinfromatics, 2008
Genome VS Transcriptome • Analysis sequence reads from genomic DNA Sequence assemble Align them to the genome • Transcriptome analysis First align the single reads to the genome Then merges the alignments to infer gene structures.
Reconstruct the whole genome from cDNA data Reconstruct the transcriptome from EST data (transcripted cDNA) Genome VS Transcriptome DNA
Problem Formulation DNA Limitation: 1 read length of the NG is relatively small. 2 read error rate(assuming 5%)
General Description Smith-Waterman • Quality Score • Slicing Site Info • Intron Length
Method 3. With Slicing Info 1. Original 2. With Quality Score 4. With Intron
Test Data • 10 000 sequences with known alignments • three different scorings • quality information • splicesite predictions • intron length