Unconfigured Ad

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • splaisan
    senior molecular biologist
    • Jun 2009
    • 32

    keep read address using tophat

    Maybe overlooking something but ...
    when I use tophat with paired reads having a name as
    @SRR479052.1 HWI-ST188:1:1101:1222:2140/1
    I end up with the second part clipped and a arbitrary read number put instead in the resulting bam as SRR479052.5415964 which does not support marking optical duplicates with picard
    Code:
    READ_NAME_REGEX=[a-zA-Z0-9]+:[0-9]:([0-9]+):([0-9]+):([0-9]+).*.
    Q: Can I preserve the full read address when using tophat with some magic argument? or should I parse both fastQ and bam to reconstitute this missing info?

    Thanks for help
    Stephane
    http://www.bits.vib.be/index.php
  • dpryan
    Devon Ryan
    • Jul 2011
    • 3478

    #2
    That's because the second part isn't part of the read name. There's an option in fastq-dump to put the original read name where it should be rather than just numbering things sequentially.

    Comment

    • splaisan
      senior molecular biologist
      • Jun 2009
      • 32

      #3
      Problem is I downloaded the fastq pre-made from the EBI repo and mapped them all :-( without figuring this out. I can fix this by patching the fatsQ but will still need to remap the whole shebang...

      Thanks for the info anyway (for next time)
      http://www.bits.vib.be/index.php

      Comment

      • splaisan
        senior molecular biologist
        • Jun 2009
        • 32

        #4
        picard markDuplicate compatible reads from SRA data

        few days later, the issue is fixed by:
        • NOT downloading the fastq files from SRA but instead the .sra formatted data using Aspera (I used the browser link)
        • Use the sratoolkit command fastq-dump (thanks Devon) to convert .sra to .fastq and split reads in paired files. The trick was here to use the specific parameter -F|--origfmt to ensure 'Defline contains only original sequence name' and that the remaining text was discarder

        The resulting command in my case was (after correcting typo!):
        fastq-dump -F --split-3 --gzip *.sra -O fastq_read_folder
        TIP: I used P|P|S|S to speed this dramatically for the 26 input files on my 24 thread machine.

        My reads have now a header line as

        @HWI-ST188:1:1101:1222:2140
        NAGACGAAGGTTCTTCAGTTAAACAGTTTAGAGCCCCATAAGAGCAAACTGTAGTGTAAAGAGGAAAAGTAAGTACAATCTTTCCAGACACACAACTAATA
        +HWI-ST188:1:1101:1222:2140
        #1:BDDDDHHHHHIIIIIIIIIIIIIHIIIIIIIIIIIIIIIIIIIIIIIIHGIFHCGIEHIIIHIIIIDEHHCHEHEEEEEECCECCCBCCBBBBCCCCA
        which after tophat mapping results for that particular read in

        HWI-ST188:1:1101:1222:2140 99 chr10 59953037 50 101M = 59953061 125 NAGACGAAGGTTCTTCAGTTAAACAGTTTAGAGCCCCATAAGAGCAAACTGTAGTGTAAAGAGGAAAAGTAAGTACAATCTTTCCAGACACACAACTAATA #1:BDDDDHHHHHIIIIIIIIIIIIIHIIIIIIIIIIIIIIIIIIIIIIIIHGIFHCGIEHIIIHIIIIDEHHCHEHEEEEEECCECCCBCCBBBBCCCCA AS:i:-1 XN:i:0 XM:i:1 XO:i:0 XG:i:0 NM:i:1 MD:Z:0C100 YT:Z:UU NH:i:1
        Running picard on such BAM data is now able to identify few 1000' optical repeats in the full sample.

        CQFD
        Last edited by splaisan; 02-15-2014, 06:14 AM. Reason: typo
        http://www.bits.vib.be/index.php

        Comment

        • GenoMax
          Senior Member
          • Feb 2008
          • 7142

          #5
          Don't see a "-F" in your fastq-dump command above. Typo?

          Comment

          • splaisan
            senior molecular biologist
            • Jun 2009
            • 32

            #6
            shame on me! corrected now (thanks)
            http://www.bits.vib.be/index.php

            Comment

            Latest Articles

            Collapse

            • GATTACAT
              Reply to Nine Things a Sample Prep Scientist Thinks About Before Sequencing
              by GATTACAT
              Love this - good data definitely starts from good input, and poor input can only give relatively poor data. I particularly like the mention of Nanodrop/absorbance based methods for quantification. It's such a toss up if you'll get an accurate reading or what amounts to a randomly generated number, and a lot of library/sequencing related issues can be traced back to poor quant.
              07-01-2026, 11:43 AM
            • SEQadmin2
              Nine Things a Sample Prep Scientist Thinks About Before Sequencing
              by SEQadmin2


              I’m not a sequencing expert. I’m a purification scientist who uses NGS to evaluate workflows my group develops. With this perspective, we think about the sample first and the NGS workflow second. The sequencer is an exceptionally honest reporter, but it can only report on what you give it, so whether you get clean, interpretable data from an NGS workflow is largely determined before you begin.

              Here are nine questions we think about, in roughly the order they matter, before...
              06-18-2026, 07:11 AM

            ad_right_rmr

            Collapse

            News

            Collapse

            Topics Statistics Last Post
            Started by SEQadmin2, 07-02-2026, 11:08 AM
            0 responses
            16 views
            0 reactions
            Last Post SEQadmin2  
            Started by SEQadmin2, 06-30-2026, 05:37 AM
            0 responses
            17 views
            0 reactions
            Last Post SEQadmin2  
            Started by SEQadmin2, 06-26-2026, 11:10 AM
            0 responses
            20 views
            0 reactions
            Last Post SEQadmin2  
            Started by SEQadmin2, 06-17-2026, 06:09 AM
            0 responses
            54 views
            0 reactions
            Last Post SEQadmin2  
            Working...