Sequence Alignment technology Chengwei Lei Fang Yuan Saleh Tamim
Goal Save time “PASS: a Program to Align Short Sequences Davide Campagna et al. Bioinformatics (2009)” Save money “Optimal pooling for genome re-sequencing with ultra- high-throughput short-read technologies, Iman Hajirasouliha, Bioinformatics (2008) ”
Keywords in both paper Reference sequence: A long Genomic sequence. Short reads: Input short strings. e.g. ATGCGTAC
Save time – PASS program PASS, a new algorithm to align short DNA sequences allowing gaps and mismatches. The performance of the program is very striking both for sensitivity and speed. For instance, gap alignment is achieved hundreds of times faster than BLAST and several times faster than SOAP, especially when gaps are allowed.
PASS Program to Align Short Sequences Performs gapped and ungapped alignment onto a reference sequence Seed words (11 and 12 bases) Short reads (7 and 8 bases) PST - calculated with the Needleman and Wunsch algorithm supplied with PASS Handles data generated by Solexa, SOLiD or 454 technologies
Approach/Algorithm
Analysis and Results Comparison of PASS with SOAP PASS has better sensitivity with words of 11 and runs at least 10 times faster
Save money - Optimal pooling method A set of experiments using the Solexa technology, based on bacterial artificial chromosome (BAC) clones, and address an experimental design problem. Basic idea: More than one BAC per lane in order to maximize the throughput of the Solexa technology, hence minimize its cost.
Input strings (short reads) Reference sequences Inputs
Normal pooling method One other hurdle in designing a globally optimal experiment is the rapid proliferation of number of possible configurations. For instance, if we would like to pool m=150 BACs into 15 groups of size=10, we would need to consider Infeasible to search all these configurations Optimal Pooling method
Input strings (short reads) Reference sequence Optimal Pooling method
Input strings (short reads) Reference sequences Optimal Pooling method
Input strings (short reads) Reference sequences Optimal Pooling method Pool
Problem How to separate the groups of short reads?
Input strings (short reads) Reference sequence Optimal Pooling method Pool
Two cases
Result
Conclusion Program for Save time “PASS: a Program to Align Short Sequences Davide Campagna et al. Bioinformatics (2009)” Algorithm for Save money “Optimal pooling for genome re-sequencing with ultra- high-throughput short-read technologies, Iman Hajirasouliha, Bioinformatics (2008) ”
Q & A