Problem running vcfutils.pl

[Balat]

Hi,
I have done a re-sequencing experiment to identify snps from candidate genes. I want to get a consensus sequence using BAM files generated by mapping reads with BWA. Ultimately I want to use the consensus fasta file in bedtools to get flanking sequences of SNPs. I have followed the commands suggested in the samtools help pages. These are the commands that I used for getting consensus fastq file.

samtools mpileup -uf ref.fa aln.bam | bcftools view -cg - | vcfutils.pl vcf2fq > cns.fq

I got the following message from vcfutils.pl and the output file contained mainly 'n's.

Use of uninitialized value $q in numeric lt (<) at /usr/bin/vcfutils.pl line 508, <> line 51404.
Use of uninitialized value $q in addition (+) at /usr/bin/vcfutils.pl line 518, <> line 51404.


Could any one please help me with this.

[Balat]

Can any one help with this?

[swbarnes2]

I think you are going to have to make at least part of the mpileup file, and examine it to see if you can eyeball the problem.

Just looking at the perl script itself:

my ($b, $q);
$q = $1 if ($t[7] =~ /FQ=(-?[\d\.]+)/);
if ($q < 0) { ...

So there's a line where the FQ regex is failing. That's what's causing the problem.

[Balat]

Hi swbarnes2,
Thank you. I can't see much of a problem in mpileup. I have attached a short mpileup file generated from a high coverage region. Could you see any problem?

[Balat]

I have tested with the older version of samtools and it seems to generate the fastq file from pileup file.

This is the pipe I used as suggested in the earlier version of help pages.

samtools pileup -cf ref.fa aln.bam | samtools.pl pileup2fq -D100 > cns.fastq

I am not sure why the mpileup is failing to get the fastq file.

[aniele_leao]

I have tested with the older version of samtools and it seems to generate the fastq file from pileup file.

This is the pipe I used as suggested in the earlier version of help pages.

samtools pileup -cf ref.fa aln.bam | samtools.pl pileup2fq -D100 > cns.fastq

I am not sure why the mpileup is failing to get the fastq file.

Hello,
I have the same problem here, but in line 544, <> line 73.
I tried samtools pileup -cf ref.fa aln.bam | samtools.pl pileup2fq -D100 > cns.fastq
But didn't work either. Do You have any suggestions?

Thank you so much!

[GenoMax]

Hello,
I have the same problem here, but in line 544, <> line 73.
I tried samtools pileup -cf ref.fa aln.bam | samtools.pl pileup2fq -D100 > cns.fastq
But didn't work either. Do You have any suggestions?

Thank you so much!

What version of samtools are you using? For samtools (0.1.19) try: http://samtools.sourceforge.net/mpileup.shtml. If you are using Samtools/Bcftools v.1.1 then the syntax is slightly different.

[aniele_leao]

I'm using version 0.1.19 and tried the command samtools mpileup -uf ref.fa aln.bam | bcftools view -cg - | vcfutils.pl vcf2fq > cns.fq
Like in the website, but with no success.

[GenoMax]

Just to make sure .. you are replacing dummy filenames (ref.fa/aln.bam) with real data when you are running this command?

If you have done that what "error" do you see?

[aniele_leao]

Just to make sure .. you are replacing dummy filenames (ref.fa/aln.bam) with real data when you are running this command?

If you have done that what "error" do you see?

Yes
This is what appear when I give the command
[mpileup] 1 samples in 1 input files
<mpileup> Set max per-file depth to 8000
[afs] 0:0.000 1:0.000 2:0.000
Use of uninitialized value in length at /usr/local/bin/vcfutils.pl line 544, <> line 73.
Use of uninitialized value in length at /usr/local/bin/vcfutils.pl line 544, <> line 73.

[GenoMax]

What aligner did you use to generate the bam files?

[aniele_leao]

Bowtie 1.1.1