Hi,
I have several separate, but kind of related questions. First I’ve imported a seqs.fna file demultiplexed using the qiime1 pipeline and I’ve use vsearch to dereplicate my sequences. Those steps were both successful, but now I’m wondering about the downstream analysis. I’ve browsed the forum and gotten more and more confused about which way is the proper way. I would ultimately like to run both an ASV clustering and a 97% OTU picking step for comparison purposes, but not sure when I can use each so here are my questions.
- If I have dereplicated the sequences using vsearch can I now use dada2 denoise? Or did I go one step too far and need to step back and use the seqs.qza file created just after import? I’m guessing yes, because this dereplicating step created a table and dada2 does that as well so I probably should use the seqs.qza file? Here is the two data types I have after dereplicating:
qiime tools peek rep-seqs.qza
UUID: ba8776d0-8285-48f2-8e66-2d08f482c904
Type: FeatureData[Sequence]
Data format: DNASequencesDirectoryFormat
qiime tools peek table.qza
UUID: 05bafc22-ee20-48b1-96a0-4e253d7ceb9e
Type: FeatureTable[Frequency]
Data format: BIOMV210DirFmt
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If I do use the seqs.qza file that comes directly from my importing step of the fna file, do I need to do any other steps to “clean” things up before using dada2 denoise?
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When I want to use OTU picking I know I’m at the correct spot to keep going on after dereplicating, but I’m having trouble importing my silva database. I had previously imported the pre-trained full-length silva from here to do dada2 on a smaller dataset that was already demultiplexed. However, when I try to use it on vsearch open-ref clustering, Qiime2 throws and error that says “Argument to parameter ‘reference_sequences’ is not a subtype of FeatureData[Sequence].” So what I’m wondering is where/how can I get the properly formatted/aligned Silva set and/or how can I import it properly? Here is my current silva qza type:
qiime tools peek silva-132-99-nb-classifier.qza
UUID: ba91648e-8216-45a0-b37e-304ef7531f9c
Type: TaxonomicClassifier
Data format: TaxonomicClassiferTemporaryPickleDirFmt
Thank you!
Alicia