CMU-SAFARI / BLEND

BLEND is a mechanism that can efficiently find fuzzy seed matches between sequences to significantly improve the performance and accuracy while reducing the memory space usage of two important applications: 1) finding overlapping reads and 2) read mapping. Described by Firtina et al. (published in NARGAB https://doi.org/10.1093/nargab/lqad004)

Geek Repo:Geek Repo

Github PK Tool:Github PK Tool

undesired 'mm_map_frag rechain' in sam file

TDDB-limagrain opened this issue · comments

Dear Blend development team,
I was interesting in testing BLEND for short read mapping. The mapping of paired-end Illumina reads against a tomato genome work perfectly but the output sam file contained 252 lines with "mm_map_frag rechain" after the PG line:

@SQ     SN:17-PSC-SL_TK14181.1.0_Chr11  LN:53848686
@SQ     SN:17-PSC-SL_TK14181.1.0_Chr12  LN:68218429
@RG     ID:var1    SM:var1     LB:Solution     PL:illumina     PU:none
@PG     ID:blend        PN:blend        VN:1.0  CL:blend -ax sr -t 4 -R @RG\tID:var1\tSM:var1\tLB:Solution\tPL:illumina\tPU:none slycopersicum.fasta.ind reads_1.fastq.gz reads_2.fastq.gz
mm_map_frag rechain
mm_map_frag rechain
...

These lines seem to be problematic for further processing with samtools:

samtools flagstat tmp.sam
[W::sam_read1_sam] Parse error at line 16
samtools flagstat: error reading from "tmp.sam"

Best regards,

Thomas

Dear @TDDB-limagrain,

Thanks for this catch. The line producing this output was originally added for debugging purposes and was inadvertently left in the code.

I have now removed this line and fixed the issue in commit 6f19e37. Could you please pull the latest version of the code, compile, and try again?

Thanks,
Can

Hi Can,
it is fixed now! thanks a lot.

Best regards,

Thomas