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  • Problems with CSHL long RNAseq ENCODE data

    Hi,

    I am trying to analyze some of the CSHL long RNAseq datasets, but I ran into some problems.

    1. When I try to use cufflinks on the BAM files, I encounter these errors:

    Warning: BAM header has 0 length or is corrupted. Try using 'samtools reheader'.
    File /mnt/genomeDB/ucsc/goldenPath/hg19/encodeDCC/wgEncodeCshlLongRnaSeq/wgEncodeCshlLongRnaSeqH1hescCytosolPapAlnRep2.bam doesn't appear to be a valid BAM file, trying SAM...
    [11:08:25] Loading reference annotation.
    [11:09:13] Inspecting reads and determining fragment length distribution.
    SAM error on line 24909: CIGAR op has zero length
    SAM error on line 26579: CIGAR op has zero length
    SAM error on line 40345: CIGAR op has zero length
    2. When I convert the BAM into SAM, I get errors about missing XS tags, which as far as I understand come from the data being mapped with STAR

    3. I then proceeded to map the data myself with TopHat2/bowtie2, but I get this error:




    [2013-12-03 18:27:15]
    Beginning TopHat run (v2.0.7)
    -----------------------------------------------
    [2013-12-03 18:27:15] Checking for Bowtie
    Bowtie version: 2.0.6.0
    [2013-12-03 18:27:15] Checking for Samtools
    Samtools version: 0.1.19.0
    [2013-12-03 18:27:16] Checking for Bowtie index files
    [2013-12-03 18:27:16] Checking for reference FASTA file
    [2013-12-03 18:27:16] Generating SAM header for /mnt/genomeDB/genomeIndices/hg19/bowtie2_index/nucleotide/hg19
    format: fastq
    quality scale: phred33 (default)
    [2013-12-03 18:27:45] Preparing reads
    left reads: min. length=76, max. length=76, 97206949 kept reads (16049 discarded)
    right reads: min. length=76, max. length=76, 97058564 kept reads (164434 discarded)
    [2013-12-03 21:07:23] Mapping left_kept_reads to genome hg19 with Bowtie2
    /mnt/software/stow/tophat-2.0.7/bin/bam2fastx: /lib64/libz.so.1: no version information available (required by /mnt/software/stow/tophat-2.0.7/bin/bam2fastx)
    /mnt/software/stow/tophat-2.0.7/bin/fix_map_ordering: /lib64/libz.so.1: no version information available (required by /mnt/software/stow/tophat-2.0.7/bin/fix_map_ordering)
    /mnt/software/stow/tophat-2.0.7/bin/bam2fastx: /lib64/libz.so.1: no version information available (required by /mnt/software/stow/tophat-2.0.7/bin/bam2fastx)
    [2013-12-04 02:21:50] Mapping left_kept_reads_seg1 to genome hg19 with Bowtie2 (1/3)
    /mnt/software/stow/tophat-2.0.7/bin/fix_map_ordering: /lib64/libz.so.1: no version information available (required by /mnt/software/stow/tophat-2.0.7/bin/fix_map_ordering)
    [2013-12-04 09:22:40] Mapping left_kept_reads_seg2 to genome hg19 with Bowtie2 (2/3)
    /mnt/software/stow/tophat-2.0.7/bin/fix_map_ordering: /lib64/libz.so.1: no version information available (required by /mnt/software/stow/tophat-2.0.7/bin/fix_map_ordering)
    Parse error at line 2849595: sequence and quality are inconsistent

    gzip: stdout: Broken pipe
    [FAILED]
    Error running bowtie:
    As I don't have much experience with this kind of data, I now am kind of stuck. Is there a way to salvage the already mapped BAM files into a cufflinks-compatible format? And what could be the reason that I encounter this error during mapping with bowtie2?

    Any help is greatly appreciated
    Last edited by rxzlmn; 12-03-2013, 08:36 PM.

  • #2
    1. You might see what the alignment looks like on those lines (i.e., lines 24909, 26579, etc.). STAR can produce output compatible with cufflinks, but the options have to be set for that.

    2. What command did you use? samtools doesn't care about XS tags (it'll print them it they're there, but they're completely optional).

    3. Your input fastq files are corrupt. If you look at line 2849595 of the filtered reads, you'll find that the sequence and QUAL lines have different lengths. This is a problem.

    Comment


    • #3
      The RNA-seq alignments on the UCSC ENCODE portal were done with a very lod (>3 years) version of STAR, and contain some non-conventional formatting, which makes it incompatible with Cufflinks and other software.

      I have remapped all of the ENCODE data with the latest version of STAR and and made public. Please check this thread for more information.

      Comment

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