All the CIGAR strings of reads mapped by Bowtie are "I"

[610617109]

Hi, guys,

I'm sorry, I make a mistake, there is no problem, but I don't know how to delete the problem.

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I faced a problem when mapping again...
I used Bowtie to align CLIP-seq reads to genome with the parameter "-v 1" which allow the reads have one mismatch. But in the result, Bowtie treat all the nucleotides of reads as insertion. For example:

2-42 16 chr11 86397621 255 23M * 0 0 GTCAACATCAGTCTGATAAGCTA IIIIIIIIIIIIIIIIIIIIIII XA:i:0 MD:Z:23 NM:i:0

Does any one have any idea what happened? What should I do to make it work?

Thanks,

Yue

[yueluo]

The 'I's you're seeing are quality scores of your read, not the CIGAR string ...
'I' in phred-33 qual is 40. Where did you get the read file and how did you perform your alignment ? I think some aligners have to option to ignore quality scores(e.g. treat all quality scores as 40).