Closed ShanSabri closed 3 years ago
The output of stats.core.csv
suggest that no reads were aligned?
sampleName,align.multihit.clusters,align.multihit.lengths,align.multihit.reads,demulti.reads,filt.reads,R1.trim.reads,R2.primer.trim.reads,R2.trim.reads,umitags.reads
ambiguous_reads,NA,NA,NA,0,NA,NA,NA,NA,NA
degenerate_reads,NA,NA,NA,316,NA,NA,NA,NA,NA
IL26296,0,0,0,267763,0,232297,0,0,267763
IL26297,0,0,0,321768,0,271878,0,0,321768
IL26298,0,0,0,260155,0,223134,0,0,260155
IL26299,0,0,0,303865,0,255801,0,0,303865
unassigned_reads,NA,NA,NA,212137,NA,NA,NA,NA,NA
Of note, these particular samples were sequenced on the a MiSeq. The MiSeq reads the i5 differently than other sequencers, the i5 is the reverse complement. So, I've specified this in the sampleInfo/sampleInfo.csv
:
sampleName,barcode1,barcode2,gRNA
IL26296,TAAGGCGA,TAGATCGCNNWNNWNN,sgRNA_A
IL26297,CGTACTAG,CTCTCTATNNWNNWNN,sgRNA_B
IL26298,AGGCAGAA,TATCCTCTNNWNNWNN,sgRNA_C
IL26299,TCCTGAGC,AGAGTAGANNWNNWNN,sgRNA_D
I wonder if the mappability is due to read quality? I have FastQC reports posted.
R1:
R2:
There might be a concern that the guides assigned to each sample may be swapped. I wonder if this is the case then would it prohibit the alignment?
Looks more like you are getting all your reads filtered out before alignment. Notice in your comment from the stats.core.csv
file that you have demultiplexed reads (demux.reads) but filtered reads (filt.reads) is equal to zero for all the samples. When that gets broken down, it looks like R1 filtering is successful, but R2 seems to fail, returning zero reads. I would take a look at your primer sequences and the beginning of your R2 reads. The qualities are low, but you should still expect something to come through. It could very well be a mistaken sequence that is included during sequence trimming that isn't actually on your reads, or maybe you've pasted the reverse comp for the sequence. Possibly you have "N" sequences in your FASTQ files and none of the reads match the primer region within the error tolerance. Let me know if any of those pan out or if they don't. I'm sure we'll figure it out.
Hi, I am having this same exact issue - had you found a solution to this, please?
Edit: Issue(s) solved. I had two main ones:
1) All my reads were getting filtered prior to alignment. To make filtering more lenient, I went into tools/rscripts/trim.R
and reduced --minSeqLength
to 20 and increased --badQualBases
to 20.
2) My run name included a full stop character .
which was preventing the sampleInfo and supp files from being read correctly.
Hi Matthew,
Great that you were able to solve this on your own, I have a bit of a backlog with this repo and little time to develop currently. Just wanted to offer my opinions / suggestions, but just take them as such since there is a lot of wiggle room for informatic processing of DNA sequence data.
minTempLength : 30
parameter in your config file. Maybe it got past the error of not having any reads, but where you able to process to completion? If you have a number of cycles though in your sequencing run that are just terrible quality, I can see how upping the --badQualBases
would permit more reads to progress. I've ran into this issue a number of times with index reads having terrible quality and reviewing the fastq outputs from demux shows the single cycle across all reads with N. Not sure if that's the case here, but could be a reason for why your first solution worked.Best of luck, feel free to reach out again if you run into any issues.
Best, Chris
I'm running into an issue where my iGUIDE processing job fails at the very last step. I've run into a similar issue before and solved by removing samples with no reads assigned (see this issue). But, this processing run does have reads assigned to each included library, see demux log below:
Error in Snakemake log:
When I read in
/home/ubuntu/iGUIDE/analysis/IP280_revcomp_bc2/output/incorp_sites.IP280_revcomp_bc2.rds
I find that the reads slots is empty:I wonder if all these reads are somehow being filtered out during processing/alignment? I've checked the
assim.log
and it seems to be showing no aligned reads for each Specimen whereas my previous iGUIDE processing runs had this information populated:I've also checked the
eval.log
and there also appears to be an error after beginning the analysis:Any insight would be greatly appreciated!