Question: Remove Soft Clipped Bases
0
gravatar for Clare
5.6 years ago by
Clare120
United States
Clare120 wrote:

I want to conduct some computations using a python script directly on some BWA aligned bam files, and to do this I need to remove the soft clipped bases. i.e. if the cigar string and read is: 2S8M CCTGGAGAAT I want to clip so it becomes: 8M TGGAGAAT

I tried to do this using clip reads in GaTK but the hardclip option is throwing errors and is unsupported.

Is there anyway to remove the soft clip bases with another piece of software.

Because my coverage is not very high, I don't want to disable softclipping in BWA, as I will loose a lot of coverage.

Thanks

bam • 4.8k views
ADD COMMENTlink modified 17 months ago by opplatek30 • written 5.6 years ago by Clare120
1

Can't you just parse the CIGAR string in your script and take care of it there?

ADD REPLYlink written 5.6 years ago by Devon Ryan90k
3
gravatar for Pierre Lindenbaum
5.4 years ago by
France/Nantes/Institut du Thorax - INSERM UMR1087
Pierre Lindenbaum120k wrote:

I just wrote a program removing the clipped bases/qual

see https://github.com/lindenb/jvarkit/wiki/Biostar84452

Example:

$  java -jar dist/biostar84452.jar samtools-0.1.18/examples/toy.sam > out.sam

@HD    VN:1.4    SO:unsorted
@SQ    SN:ref    LN:45
@SQ    SN:ref2    LN:40
@PG    ID:0    PN:com.github.lindenb.jvarkit.tools.biostar.Biostar84452    VN:b5ebf67dd2926d8a6afadb4d1e36a4959508057f    CL:samtools-0.1.18/examples/toy.sam
(...)
r002    0    ref    9    0    2I6M1P1I1P1I4M2I    *    0    0    AAAGATAAGGGATAAA    *
(...)


$ grep r002 samtools-0.1.18/examples/toy.sam
r002    0    ref    9    30    1S2I6M1P1I1P1I4M2I    *    0    0    AAAAGATAAGGGATAAA    *
ADD COMMENTlink written 5.4 years ago by Pierre Lindenbaum120k
1

this tool was cited in the suppl. mat. of http://genome.cshlp.org/content/early/2017/10/05/gr.218032.116.full.pdf+html

ADD REPLYlink written 17 months ago by Pierre Lindenbaum120k
2
gravatar for opplatek
17 months ago by
opplatek30
Czech Republic
opplatek30 wrote:

bamutils / removeclipping works also very nice

P.S. I know the post is very old but this might be handy for somebody else reading this post in the future.

ADD COMMENTlink modified 17 months ago • written 17 months ago by opplatek30
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