I’ve lost quite a lot of time trying to align color-space RNA-Seq reads. SHRiMP paper explains nicely, why it’s important to align SOLiD reads in color-space, instead of converting color-space directly into sequence-space. Below, you can find the simplest solution I have found, using tophat, relying on bowtie mapper (bowtie2 doesn’t support color-space) and color-space reads in .csfasta.
# generate genome index in color-space bowtie-build --color GENOME.fa GENOME # get SOLiD reads from SRA if you don't have them already in .csfasta abi-dump SRR062662 # tophat splice-aware mapping in color-space mkdir tophat ref=REFERENCE_DIR/GENOME for f in READS_DIR/*.csfasta; do s=`echo $f | cut -f2 -d'/' | cut -f1 -d'.'` if [ ! -d tophat/$s ]; then echo `date` $f $s tophat -p 4 --no-coverage-search --color -o tophat/$s --quals $ref $f READS_DIR/${s}_QV.qual fi done