Unconfigured Ad

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • DNAmethylome
    Member
    • Oct 2012
    • 13

    #1

    Tophat chromosome position greater than chromosome size

    I use tophat to map the rna-seq reads (paired-end). It seems that some of the reads in the .sam do not make sense. Please see some examples below:

    Example line 1:
    NB500923:20:H7WCJBGXX:1:12109:13961:14748 385 chr1 11646 3 151M chr22 114359002 0 CTTTTGGATTTTTGCCAGTCTAACAGGTGAAGCCCTGGAGATTCTTATTAGTGATTTGGGCTGGGGCCTGGCCATGTGTATTTTTTTAAATTTCCACTGATGATTTTGCTGCATGGCCGGTGTTGAGAATGACTGCGCAAATTTGCCGGAT AAAAAEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE<EEEEEEEEEEEEEEEEEEEEE/AEEEEEEEEAEEEEEEEEEEEEEEEEEEEEEEEEAEA/EAA<EEEEEEAEA/<AEE XA:i:0 MD:Z:151 NM:i:0 NH:i:2 CC:Z:chr15 CP:i:102519374 HI:i:0

    In the above line, it says the start position of the mate on chr22 is 114359002, however, the size of the chr22 is only 51304566

    Example line 2:
    NB500923:20:H7WCJBGXX:1:23107:14442:20318 323 chr1 11696 0 151M chrUn_GL000249 155257832 0 GTGATTTGGGCTGGGGCCTGGCCATGTGTATTTTTTTAAATTTCCACTGATGATTTTGCTGCATGGCCGGTGTTGAGAATGACTGTGCAAATTTGCCGGATTTCCTTCGCTGTTCCTGCATGTAGTTTAAACGAGATTGCCAGCACCGGGT AAAAAEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEAEEEEEEEEEEEEEAEEEEEAEEEEEEE<EEEEEEEEEEEEEEEAAEEA<EEEEEE XA:i:2 MD:Z:85C21T43 NM:i:2 NH:i:8 CC:Z:= CP:i:11696 HI:i:4

    It says the start position of the mate on chrUn_GL000249 is 155257832, however, the total size of chrUn_GL000249 is only 38502.

    Can anyone tell how this could happen? and how to fix the file?

    Thanks,
  • DNAmethylome
    Member
    • Oct 2012
    • 13

    #2
    Can anyone help?

    Comment

    • dpryan
      Devon Ryan
      • Jul 2011
      • 3478

      #3
      Looks like this is a bug in the version of tophat2 that you're using. If you're using the most recent version, then please report this to the authors so they can fix it.

      Comment

      Latest Articles

      Collapse

      • SEQadmin2
        16S/ITS Profiling vs. Shotgun Metagenomics: What Changes in Your Workflow?
        by SEQadmin2




        NGS has revolutionized clinical microbiology by offering new ways to identify and surveil pathogens without prior knowledge of the target. One popular approach is 16S rRNA and ITS amplicon sequencing, which targets specific microbial markers. But studies are increasingly incorporating shotgun metagenomics, a technique that sequences all DNA from a sample without targeting specific microbial markers. This approach allows more detailed taxonomic classification, detection...
        Yesterday, 06:46 AM
      • SEQadmin2
        Multiomic Liquid Biopsy: What DNA/RNA Panels Reveal That DNA Alone Can’t
        by SEQadmin2



        Tumors contain complex mixtures of cell populations that evolve in response to treatment and host-specific factors. Tissue biopsies provide only static snapshots of a tumor’s state. But what if we could follow that evolution over time using a minimally invasive technique?

        Liquid biopsies can detect tumor-derived material circulating in the bloodstream, providing a way to study treatment response, detect emerging resistance, and discover new biomarkers. Circulating
        ...
        10-14-2026, 09:55 AM

      ad_right_rmr

      Collapse

      News

      Collapse

      Topics Statistics Last Post
      Started by SEQadmin2, 10-28-2026, 09:57 AM
      0 responses
      29 views
      0 reactions
      Last Post SEQadmin2  
      Started by SEQadmin2, 10-28-2026, 09:51 AM
      0 responses
      20 views
      0 reactions
      Last Post SEQadmin2  
      Started by SEQadmin2, 10-22-2026, 11:13 AM
      0 responses
      71 views
      0 reactions
      Last Post SEQadmin2  
      Started by SEQadmin2, 10-22-2026, 10:48 AM
      0 responses
      48 views
      0 reactions
      Last Post SEQadmin2  
      Working...