Unconfigured Ad

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • rwmills
    Junior Member
    • Apr 2015
    • 2

    bcftools doesn't call suspected indel

    Hello-

    I am looking for CRISPR-mediated indels using samtools/bcftools 1.2, but bcftools call doesn't report an apparent indel.

    If I use this command:
    samtools mpileup -guf ref.fasta sortedReads.bam | bcftools call -c - > out.vcf

    and inspect the output vcf, I find in the expected indel location that only ref exists:

    Code:
    Human	3078	.	A	.	283.236	.	DP=574;VDB=0.00187095;SGB=-0.590765;RPB=0.623577;MQB=0.639386;BQB=0.0765187;MQ0F=0;AF1=0;AC1=0;DP4=531,0,5,0;MQ=40;FQ=-281.989;PV4=1,0.0104987,1,1	GT:PL	0/0:0
    Human	3079	.	A	.	283.236	.	DP=578;VDB=0.958818;SGB=-0.616816;RPB=0.337168;MQB=0.757481;BQB=0.00621451;MQ0F=0;AF1=0;AC1=0;DP4=524,0,6,0;MQ=40;FQ=-281.989;PV4=1,4.05418e-05,1,2.10095e-14	GT:PL	0/0:0

    However, if I backup a step and use
    samtools mpileup -f ref.fasta sortedReads.bam > out.pileup

    and inspect the output pileup file I find the below, which I believe indicates that site 3078 is reference, but 3079 has a 3bp indel. If so, what options should I pass to the caller to report these indels when I setup my pipeline (I don't want to manually inspect every pileup!)?

    Code:
    Human	3078	A	537	*............................................................................................G......................+3ATT..................................................................................+3ATT................................................................................+3TTT..+3TTTCGGG............................................................................................................+3ATT...............+3ATT..................................................................................................................................	HHHHE?H;GGAHHE>ECF/FHC/GHHHHHGHAHHHHHHF/FHHH/H/HHHEHEHHHHHGHHHGCHHG?HHHHHH?HHHHHHGGHHHHGFHHHEEGH0FEAHHGG>HHHHHHHAGE/?GHHHHHHF/<67HHHHHHHGEHHHG/HHHHHHH/>HCHHHGHHHGH>HHHHGFHHAGGHHHHEH//H9H9HFGHCHH/GH:BHHFG/CEGG/?/:F>EFFFEHH/FHHGFGG/GH/HFHHHHH/HGEHHHHHGHHHHHHHHGGHH//G?CFEFFHHH9<85;=/GG3H?E3HBH?HGFHFH/GHG?HGHGHHFCHHH/HHECHFEHHHHEHHGHHFA/GEFFAH/EHHH/HHHEEGGFAGH/EHF/HHHHHGHEGGHH?HEH//GHHG?HFFHH:GHFGGHFH/EHHGH:HGF/FHHHHHHHGHGEHGCHFHHHEHH/HHHHHHHHHHHGHHHHHHHHHHHHHHHHHHHHHHHHFHHHHHHHHHHHHHAHGHHHHHHHHHFHHHHHHHHHHHHHHHHHHHGHHGHHHHGHGHHGHC03B4
    Human	3079	A	531	*.+3TTG.+3TTG.+3TTG..+3TTG.+3TCG...+3TTG.+3TTG..+3TTG.+3TTG.+3TTG..+3TTG.+3TTG.+3TTG..+3TTG.+3TTG.+3TTG.+3TTG...+3TTG.+3TTG.+3TCG.+3TTG...+3TTG.+3TTG....+3TTG.+3TTG...+3TTG.+3TTG.+3TTG.+3TTG.+3TTG...+3TTG.+3TTG..+3TCG.+3TTG.+3TTG...+3TTG.....+3TTG.+3TTG....+3TTG..+3TTG.+3TTG...+3TTG.+3TTG.......+3TTG.+3TTG..+3TTG..+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG...+3TTG.+3TTG..+3TTG.+3TTG.+3TTG..+3TTG..+3TTG.+3TTG...+3TTG...+3TTG.+3TTG.+3TTG..+3TTG.+3TTG.+3TTG...+3TTG...+3TTG..+3TTG.+3TTG.+3ATG.+3ATG..............+3CTG.+3CTG.............................-5CACAT....+3GTG...+3TAG.+3TAG..+3TCG.+3TCG..+3TCG...+3TGG..+3TGG....+3TGG.+2TG....+3TTC.+3TTC..+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTTGG+3TTGT+3TTG.+3TTG...+3TTG..+3TGG.+3TTG.+3TTG..+3TTG.+3TTG.+3TTG...+3TTG.+3TTG....+3TTG..+3TTG.+3TTG.....+3TTG..+3TTG.+3TTG...+3TTG.+3TTG..+3TTG....+3TTG.+3TTG.....+3TTG.+3TTG..+3TTG...+3TTG..+3TTG.+3TTG...+3TTG.+3TTG.+3TTG.+3TAG.+3TTG.......+3TTG.+3TTG.+3TTG..+3TTG.+3TTG...+3TTG.+3TTG.+3TTG..+3TTG.+3TTG.+3TTG...+3TTG.....+3TTG.+3TTG.+3TTG.+3TTG..+3TGG.+3TTG..+3TTG.+3TTG..+3TTG.+3TTG.+3TTG.+3TTG.+3TTG..+3TTG.+3TTG..+3TCG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG..+3TTG.+3TTG.+3TTG.+3TTG..+3TTG.+3TTG..+3TTG..+3TTG...+3TTG.+3TTG.+3TTG.+3TCG.+3TTG.+3TTG.+3TTG..+3TTG...+3TCG.+3TTG.+3TTG.+3TTG.+3TTG....+3TTG.+3TTG..+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG..+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.-5CACAT.+3TTG.+3TTG..+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG..+3TTG.+3TTG.+3TTG.+3TTG.+3TTG.+3TTG..+3TTGCC.+3TTGC	HH;;/H/FH9/E//E/AFEHF;6HHHHG/HGHHHHHHGBGHHH?;GHEEEHHHGHHHHHHHH;HEHGEHHHHH/HHHHHHG/HHFF//CHG///G?EE9HHHG;HHHHHHHEH/F/HHH=HG/2G723HHHHEHH/EHHHA>H>EEFHH/EH>HHHHHHHCH/GHHHEEHH2///;/H46/=H6H6/D/;FCCB;52/G//5;5/9=//75=99///>D/HHEGHH>HE/H>HHHHH6HEAHHEHH6HHH6HHHHE/=6C/G8/D9//F;;901/GG3G8?GH;H9HH9GEHF=HH/HHHFHG=FHHH/HHF/H5/HGFHHHHHHH:AC/FFFEH/?HHH?HH;6HHHEEH/64HH//HHFHHEH/HHGFF;HEC4;;H6=HEEHHHHFEE;GH>FH;GH;;//CAHHH;HH/HEA;G?C;HG;HHD/;:E;H;;;;;;;;;;;=;;;;;;;;;;;<;;;;;;H=<;;;;;;H;;;;;2;;2;;;<;;=;;>;;;<;;;;;;;;;;;;;;;;;;;;;;H<;<;;<G;10:1
    Last edited by Brian Bushnell; 04-13-2015, 01:54 PM. Reason: added code tags
  • Richard Haigh
    Junior Member
    • Sep 2015
    • 2

    #2
    Hi rwmills

    I am having similar problems with bcftools call - I am using old test data which I know contains 60 snps and 5 indels and Varscan has no problem identifying indels from the data but bcftools will only see the snps whatever modifiers I add to the command. Did you ever resolve this?

    Richard

    Comment

    • rwmills
      Junior Member
      • Apr 2015
      • 2

      #3
      Originally posted by Richard Haigh View Post
      Hi rwmills

      I am having similar problems with bcftools call - I am using old test data which I know contains 60 snps and 5 indels and Varscan has no problem identifying indels from the data but bcftools will only see the snps whatever modifiers I add to the command. Did you ever resolve this?

      Richard
      Hi Richard-

      I was never able to get bcftools to make this call even with substantial data grooming before passing to the caller. In my case, it is likely due to the algorithm being confounded by extreme read depth (>8000), as VarScan's overview mentions. VarScan easily calls this insertion as well as a deletion I hadn't noticed before.

      Comment

      • Richard Haigh
        Junior Member
        • Sep 2015
        • 2

        #4
        Hi Richard-

        I was never able to get bcftools to make this call even with substantial data grooming before passing to the caller. In my case, it is likely due to the algorithm being confounded by extreme read depth (>8000), as VarScan's overview mentions. VarScan easily calls this insertion as well as a deletion I hadn't noticed before.
        Thanks for the reply. I have also tried with data with various read depths and all no good - I'm starting to think that the samtools 1.2 version of bcftools call is just broken for indels. In the end I gave up and have managed to bodge my pipeline using the newer version of Varscan (3.2.9) which gives all the right indels but now has a more acceptable vcf output. A simple bit of editing with awk and the files went into snpEff with no problem.

        Comment

        Latest Articles

        Collapse

        • 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
        • SEQadmin2
          From Collection to Sequencing: Why Sample Preparation and Preservation Define Sequencing Data
          by SEQadmin2


          Data variability is still an issue in sequencing technologies despite the advances in reproducibility and accuracy of these platforms. But the problem does not originate in the sequencing itself, but in the previous steps, before the sample reaches the sequencer.


          The first step is collection, followed by preservation and sample preparation for analysis. Most scientists overlook those steps, but not being careful might just be skewing the experiment’s results.
          ...
          06-02-2026, 10:05 AM

        ad_right_rmr

        Collapse

        News

        Collapse

        Topics Statistics Last Post
        Started by SEQadmin2, Yesterday, 11:10 AM
        0 responses
        8 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 06-17-2026, 06:09 AM
        0 responses
        44 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 06-09-2026, 11:58 AM
        0 responses
        104 views
        0 reactions
        Last Post SEQadmin2  
        Started by SEQadmin2, 06-05-2026, 10:09 AM
        0 responses
        125 views
        0 reactions
        Last Post SEQadmin2  
        Working...