Hi Ravi,
I got around this problem by using the fastq interlacer to join reads in to a single file, then use deinterlacer to output only reads that have a pair in the correct order.
You may need to alter read IDs first by adding /1 and /2 to the end (see interlacer help text). I used unix command line sed but I'm sure you can use galaxy tools to do this.
Shaun
Quoting Ravi Karra ravi.karra@gmail.com on Wed, 22 Feb 2012 12:29:18 -0500:
Hello,
I have Illumina 76bp paired end data for a zebrafish RNA-seq experiment and am basically stuck while trying to pre-process my data prior to using Tophat/CuffDiff.
For each sample, I have a read1 fastq file and a paired read2 fastq file. After using FASTQ Groomer, I trimmed the ends using FASTQ quality trimmer with a threshold quality score of 20 ans a window size of 1 (I think that will essentially lop off the end of the read until the quality score is >= 20). Next, I trimmed the adapters using Clip.
What I am left with is a modified read1 fastq file and a modified read2 file, where the pairs are not in the same order and some reads are left without pairs. From what I have read, I don't think TopHat can incorporate paired end data that is out of order.. I tried to get around the ordering issue using FASTQ joiner, but this tool is not able to join the reads (return is 0 joined reads). I am not really sure why FASTQ joiner didn't work for me and am looking for suggestions of what to try next.
Thanks! ravi ___________________________________________________________ The Galaxy User list should be used for the discussion of Galaxy analysis and other features on the public server at usegalaxy.org. Please keep all replies on the list by using "reply all" in your mail client. For discussion of local Galaxy instances and the Galaxy source code, please use the Galaxy Development list:
http://lists.bx.psu.edu/listinfo/galaxy-dev
To manage your subscriptions to this and other Galaxy lists, please use the interface at: