Stormbow: A Cloud-Based Tool for Reads Mapping and Expression Quantification in Large-Scale RNA-Seq Studies

Figure 1

Stormbow in action. S3 centralizes data storage. The large volumes of data are imported into or exported from S3 through Amazon Import and Export services. Multiple EC2 instances are launched automatically from a local Linux workstation by the Perl script, Stormbow.pl. All EC2 instances fetch sequence data from S3 and upload result files to S3. The key steps and tasks performed by each EC2 instance are detailed in the right of the figure. The Merge.pl script combines the gene counts in each sample into a consolidated count table that may be used as input to differential analysis tools, such as DESeq and edgeR.