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  • Need urgent help for Tophat + Cufflinks !!!

    Hi folks,

    I'm running tophat (tophat -o output_dir a_ref a.fq) for alignment and cufflinks (cufflinks -o output_dir accepted_hits.bam) for assembles transcripts. The reads are single-end.

    This is my command line:
    tophat -o tophat_60PO ./hg19 ./60PO.fastq
    cufflinks -o cufflinks_60PO tophat_60PO/accepted_hits.bam

    The results:
    Step 1:
    $ ls -l tophat_60PO
    -rw-rw-r-- 1 fangquan fangquan 1104315390 Aug 4 09:45 accepted_hits.bam
    -rw-rw-r-- 1 fangquan fangquan 52 Aug 4 09:35 deletions.bed
    -rw-rw-r-- 1 fangquan fangquan 54 Aug 4 09:35 insertions.bed
    -rw-rw-r-- 1 fangquan fangquan 52 Aug 4 09:35 junctions.bed
    -rw-rw-r-- 1 fangquan fangquan 70 Aug 4 05:54 left_kept_reads.info
    drwxrwxr-x 2 fangquan fangquan 4096 Aug 4 09:04 logs


    The results are weird, deletions.bed, insertions.bed, and junctions.bed are EMPTY files, with only track name.

    #############################################
    #############################################
    Step 2:
    $ls -l cufflinks_60PO
    -rw-rw-r-- 1 fangquan fangquan 129 Aug 5 14:53 genes.fpkm_tracking
    -rw-rw-r-- 1 fangquan fangquan 129 Aug 5 14:53 isoforms.fpkm_tracking
    -rw-rw-r-- 1 fangquan fangquan 0 Aug 5 14:53 transcripts.gtf


    The results are weird again, three files are all EMPTY. And I tried all ten samples but all end up weird results.



    Can anyone help me figure out what's going wrong ? I have ten samples and all of them have the same weird results. Waiting for your replies !

    Thanks,
    Quan
    Last edited by fangquan; 08-09-2011, 06:15 PM. Reason: Typo

  • #2
    what is your reads length?
    please try to set --segment-length parameter using half length of the reads
    Originally posted by fangquan View Post
    Hi folks,

    I'm running tophat (tophat -o output_dir a_ref a.fq) for alignment and cufflinks (cufflinks -o output_dir accepted_hits.bam) for assembles transcripts. The reads are single-end.

    This is my command line:
    tophat -o tophat_60PO ./hg19 ./60PO.fastq
    cufflinks -o cufflinks_60PO tophat_60PO/accepted_hits.bam

    The results:
    Step 1:
    $ ls -l tophat_60PO
    -rw-rw-r-- 1 fangquan fangquan 1104315390 Aug 4 09:45 accepted_hits.bam
    -rw-rw-r-- 1 fangquan fangquan 52 Aug 4 09:35 deletions.bed
    -rw-rw-r-- 1 fangquan fangquan 54 Aug 4 09:35 insertions.bed
    -rw-rw-r-- 1 fangquan fangquan 52 Aug 4 09:35 junctions.bed
    -rw-rw-r-- 1 fangquan fangquan 70 Aug 4 05:54 left_kept_reads.info
    drwxrwxr-x 2 fangquan fangquan 4096 Aug 4 09:04 logs


    The results are weird, deletions.bed, insertions.bed, and junctions.bed are EMPTY files, with only track name.

    #############################################
    #############################################
    Step 2:
    $ls -l cufflinks_60PO
    -rw-rw-r-- 1 fangquan fangquan 129 Aug 5 14:53 genes.fpkm_tracking
    -rw-rw-r-- 1 fangquan fangquan 129 Aug 5 14:53 isoforms.fpkm_tracking
    -rw-rw-r-- 1 fangquan fangquan 0 Aug 5 14:53 transcripts.gtf


    The results are weird again, three files are all EMPTY. And I tried all ten samples but all end up weird results.



    Can anyone help me figure out what's going wrong ? I have ten samples and all of them have the same weird results. Waiting for your replies !

    Thanks,
    Quan

    Comment


    • #3
      Thanks,

      The read length is 40 bp. I will try out your suggestion.

      Originally posted by liuxq View Post
      what is your reads length?
      please try to set --segment-length parameter using half length of the reads

      Comment


      • #4
        Thanks,

        The read length is 40 bp. I will try out your suggestion.

        Originally posted by liuxq View Post
        what is your reads length?
        please try to set --segment-length parameter using half length of the reads

        Comment


        • #5
          Did you sort and index your "accepted_hits.bam" from Tophat?

          Comment


          • #6
            Hi, Thanks for your reply, but I thinks it's already sorted. This is what I saw from cufflinks manual.

            "The SAM file supplied to Cufflinks must be sorted by reference position. If you aligned your reads with TopHat, your alignments will be properly sorted already. If you used another tool, you may want to make sure they are properly sorted as follows: sort -k 3,3 -k 4,4n hits.sam > hits.sam.sorted
            "

            Originally posted by chenyao View Post
            Did you sort and index your "accepted_hits.bam" from Tophat?

            Comment

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