HTSeq-count on bam

[dvanic]

Hi!
Is there a way to directly run htseq-count on a bam file? I know that htseq supports bam input via HTSeq.BAM_Reader(), but is there a flag to tell the htseq-count script that I'm using a bam?

Or which file in the source code (and how) do I modify to configure it to work with bams and not sams???

Thanks in advance!

[hlwright]

Hi

I have EXACTLY the same question. Does htseq take BAM files, or do you have to convert to SAM first (don't want to do this if I don't have to)?

Thanks

[dpryan]

If you're using the command line version, you can just use:

samtools view file.bam | htseq-count (options) - GTF > counts.txt

where GTF is the GTF file and (options) are whatever options are appropriate.

[hlwright]

dpryan - that worked brilliantly, thanks!

)

[astazangasta]

counting reads

If anyone else is trying this, be advised that HTseq count requires reads to be name-sorted. If you usually keep your bam coordinate-sorted, like I do, and you have paired-end reads, you need to do a bit more work to get it in the right shape, otherwise HTseq will end up skipping huge numbers of reads. I do:

samtools sort -on - output | samtools view -h - | htseq_count etc.

[Him26]

samtools sort -on - output | samtools view -h - | htseq_count etc.

Could you expand on how you pipe-in to htseq-count?
I get an error saying I need to provide two arguments to htseq-count.
I just left it blank on the htseq-count commend assuming that it will know.
my code is like below:

 | htseq-count -m{option}  annotation.gtf >output.count

Thank you.

[dpryan]

samtools sort -on file.bam | samtools view - | htseq-count (options) - GTF > counts.txt

Or something like that. The "-" means read from the pipe/standard input in both samtools and htseq-count.

[Him26]

Thank you dpryan for the quick reply.
I tried the following code and I get the following error? any suggestions?

 samtools sort -on -m 300000000 accepted_hits.bam |samtools view -h - |htseq-count -m intersection-strict -  /genome/gencode.v18.annotation.gtf > hits.count

Usage: samtools sort [options] <in.bam> <out.prefix>

Options: -n sort by read name
-f use <out.prefix> as full file name instead of prefix
-o final output to stdout
-l INT compression level, from 0 to 9 [-1]
-@ INT number of sorting and compression threads [1]
-m INT max memory per thread; suffix K/M/G recognized [768M]

[bam_header_read] EOF marker is absent. The input is probably truncated.
[bam_header_read] invalid BAM binary header (this is not a BAM file).
[main_samview] fail to read the header from "-".
100000 GFF lines processed.
200000 GFF lines processed.
300000 GFF lines processed.
400000 GFF lines processed.
500000 GFF lines processed.
600000 GFF lines processed.
700000 GFF lines processed.
800000 GFF lines processed.
900000 GFF lines processed.
1000000 GFF lines processed.
1100000 GFF lines processed.
1200000 GFF lines processed.
1300000 GFF lines processed.
1400000 GFF lines processed.
1500000 GFF lines processed.
1600000 GFF lines processed.
1700000 GFF lines processed.
1800000 GFF lines processed.
1900000 GFF lines processed.
2000000 GFF lines processed.
2100000 GFF lines processed.
2200000 GFF lines processed.
2300000 GFF lines processed.
2400000 GFF lines processed.
2500000 GFF lines processed.
2600000 GFF lines processed.
2614562 GFF lines processed.
Error occured when reading first line of sam file.

[Exception type: StopIteration, raised in count.py:83]

[bruce01]

[bam_header_read] EOF marker is absent. The input is probably truncated.
[bam_header_read] invalid BAM binary header (this is not a BAM file).
[main_samview] fail to read the header from "-".

So your BAM is not complete, try realigning, or use a different BAM.

[dpryan]

You may also just see if the following produces the same result:

samtools sort -n -m 300000000 accepted_hits.bam namesorted

If so, then bruce01 is correct that your original BAM file is truncated. It's unclear which of the samtools steps is producing the fatal error and this would determine which it is (I too suspect that the original BAM file is just truncated).

[flek]

If anyone else is trying this, be advised that HTseq count requires reads to be name-sorted. If you usually keep your bam coordinate-sorted, like I do, and you have paired-end reads, you need to do a bit more work to get it in the right shape, otherwise HTseq will end up skipping huge numbers of reads. I do:

samtools sort -on - output | samtools view -h - | htseq_count etc.

I just came across the same problem and while browsing the htseq documentation I found out that there is a new option in version 0.6.1 that allows to read bam files which are sorted by position.

htseq_count -r pos etc.

More at their documentation

[dstorey]

It unfortunately has a well known bug that causes the memory buffer to overflow sometimes. Named sort appears to be the most consistent method for getting a run completed.

[tsalem]

Now, I think htseq can take directly the bam file, we only need to use the -f option as follows


htseq-count -f bam <file>.bam <file>.gtf > genes_count.txt


is i am Wrong? I tried it and it works

[GenoMax]

after i run the command
htseq-count -f bam <file>.bam <file>.gtf > genes_count.txt

i got the following error,


Warning: Read UNC13-SN749_48:5:2105:5602:87765/2 claims to have an aligned mate which could not be found in an adjacent line.
Error occured when processing SAM input (record #40 in file sorted_genome_alignments.bam):
tid -1 out of range 0<=tid<25
[Exception type: ValueError, raised in csamfile.pyx:535]

is any one have an idea why this error? Thanks in advance

When you did QC/trimming of the data was a PE-read aware program used (to keep the pairs of reads in sync in both files) with the two data files at the same time (R1/R2)? It is possible that reads in your files went out of sync and this is resulting in the error above.

[tsalem]

Actually, I didn't do any thing with the files, I just got the .gtf file from The ucsc.
and the .bam file from my advisor. and i am trying to get genes count from .bam file.

is possible to let me know how i can check if the pairs of reads in sync in both files

Thanks