Htseq-Count Not Giving Counts For Mirna Alignment To Mirbase

Question: Htseq-Count Not Giving Counts For Mirna Alignment To Mirbase

5.6 years ago by

University of Helsinki, Finland

Hi,

I was trying to get the counts of miRNAs using htseq-count. The sam file is generated from adapter trimmed miRNA-seq alignment (bowtie) against miRBase mature miRNAs.

The sam file look like this:

HISEQ2000:383:C2452ACXX:1:2316:21334:99296    0    hsa-miR-30c-5p    1    255    23M    *    0    0    TGTAAACATCCTACACTCTCAGC    @@@DDDD>FFHFBH<C:FB9EE:    XA:i:0    MD:Z:23    NM:i:0
HISEQ2000:383:C2452ACXX:1:2316:21266:99322    0    hsa-miR-486-5p    1    255    22M    *    0    0    TCCTGTACTGAGCTGCCCCGAG    @C@FFFDFFHAHHIIIIIIEED    XA:i:0    MD:Z:22    NM:i:0

The reference fasta file used to create bowtie index:

>hsa-let-7a-5p
TGAGGTAGTAGGTTGTATAGTT
>hsa-let-7a-3p
CTATACAATCTACTGTCTTTC

Gtf file used :

hsa-mir-6859-1    .    miRNA_primary_transcript    17369    17436    .    -    .    ID "MI0022705"; Alias "MI0022705"; Name "hsa-mir-6859-1"
hsa-miR-6859-5p    .    miRNA    17409    17431    .    -    .    ID "MIMAT0027618"; Alias "MIMAT0027618"; Name "hsa-miR-6859-5p"; Derives_from "MI0022705"

I am not getting any counts for miRNAs based on these files with htseq-count. At the same time, I can see from the sam file that there are mappings to miRNAs.
htseq command used:

htseq-count --mode=intersection-strict --stranded=no --type=miRNA --idattr=Name  eg.sam  hsa.gff3

Could anyone advise me whether there is anything wrong in this approach or in the files I have used to get the counts ?

Thanks

• 4.8k views

ADD COMMENT • link •

modified 5.6 years ago by Jeremy Leipzig ♦ 18k • written 5.6 years ago by Preethy Nair • 0

As sanders.muc noted, it looks like your annotation won't match the alignments. How long is the "hsa-miR-6859-5p" transcript in the fasta file? If it's less than ~17.4kb then this will never work. Why don't you just look at how many reads map to each contig in the resulting BAM (look at samtools idxstats)? Presuming you first filtered out multimappers, that would seem to work.

ADD REPLY • link written 5.6 years ago by Devon Ryan ♦ 91k

5.6 years ago by

Jeremy Leipzig ♦ 18k

Philadelphia, PA

Jeremy Leipzig ♦ 18k wrote:

You don't really need HT-Seq to do this since there are no ranges involved

hairpins <- read.DNAStringSet(paste(hiseqDataDir,"refs/hairpin.fa",sep=""),use.names=TRUE)
names(hairpins)<-str_match(names(hairpins),"^\\S+") 
hairpinGR<-GRanges(names(hairpins),IRanges(1,width(hairpins)),strand="*")
bamView<-BamViews(bamPaths=bamPaths,bamSamples=bamSamples,bamRanges=hairpinGR)
bamcounts<-countBam(bamView)

ADD COMMENT • link written 5.6 years ago by Jeremy Leipzig ♦ 18k

Thanks a lot.

ADD REPLY • link written 5.4 years ago by Preethy Nair • 0

Hi, I have the same problem and I tried every step that you write. I also have an index of my bam sequence. However in the last one I have this error:

> bamcounts <- countBam(bamView)
Error in .BamViews_delegate("countBam", file, fun, ..., param = param) :
  'countBam' failed on ''
In addition: Warning messages:
1: In doTryCatch(return(expr), name, parentenv, handler) :
  space 'hsa-let-7a-1' not in BAM header
2: RemoteWarning
  elements: 1
  UnspecifiedError: value[[3L]](cond)
'countBam' failed
  file: /home2/result/ann/mapped/SRR433866
  index: /home2/result/ann/mapped/SRR433866.bam

ADD REPLY • link written 4.9 years ago by Kato • 50

usually the index would be called SRR433866.bam.bai. Show us

samtools view -H /home2/result/ann/mapped/SRR433866.bam

ADD REPLY • link modified 4.9 years ago • written 4.9 years ago by Jeremy Leipzig ♦ 18k

Thanks for the script

Vijay

ADD REPLY • link modified 3.8 years ago • written 3.8 years ago by vijay.bhaaskarla • 0

5.6 years ago by

Simon Anders • 30

Heidelberg, Germany

Simon Anders • 30 wrote:

I don't understand your GFF file: What to the coordinate intervals mean? Is this the position of the miRNA on the chromosome?

Also, note that htseq-count is meant to count reads mapped to the genome. You have mapped, however, to a reference which lists only the miRNA transcriptome and each miRNA as a separate sequence. Hence, you could just look at the 3rd column of your SAM file and count based on this.

ADD COMMENT • link written 5.6 years ago by Simon Anders • 30

5.6 years ago by

liran0921 • 110

liran0921 • 110 wrote:

I suppose your gtf file is downloaded from Mirbase. Actually the coordinates in this file is based on the alignment with bovine genome. So you should align your reads file with the same bovine genome if you want to use this gtf file for read counting.

ADD COMMENT • link written 5.6 years ago by liran0921 • 110

Please log in to add an answer.

Similar posts • Search »