qiime2R
Qiime
My sequencing was done by Ion Torrent which made Qiime a bit difficult to use because of lacking documentation. I followed, mostly, this post by Carli Jones: https://forum.qiime2.org/t/possible-analysis-pipeline-for-ion-torrent-16s-metagenomics-kit-data-in-qiime2/13476.
Pipeline
- Import fastq using “manifest” file format
- Perform
DADA2
- Explore
feature counts
- Create phylogenetic tree using
SEPP (fragment insertion)
Alpha rarefaction
Core metrics analysis
Qiime outputs, R plots
For this project data visualization is the most important part because it’s pilot data for a new project. qiime2R has really good documentation; for details see https://github.com/jbisanz/qiime2R.
First I uploaded the Qiime2 output files needed to make my plot which was very straightforward following the documentation by Dr. Jordan Bisanz.
metadata<-read_tsv("warfgi_qiime_meta.tsv")
colnames(metadata)[colnames(metadata) == "sampleid"] = "SampleID"
uwunifrac<-read_qza("unweighted_unifrac_pcoa_results.qza")
shannon<-read_qza("shannon_vector.qza")$data %>% rownames_to_column("SampleID")
Plotting
Again, using code from the qiime2r documentation, I plotted the first two PCs with sizing by Alpha Diversity.
uwunifrac$data$Vectors %>%
select(SampleID, PC1, PC2) %>%
left_join(metadata) %>%
left_join(shannon) %>%
ggplot(aes(x=PC1, y=PC2, color=`samplegroup`, size=shannon)) +
geom_point(alpha=0.8) + #alpha controls transparency and helps when points are overlapping
theme_q2r() +
scale_size_continuous(name="Shannon Diversity") +
scale_color_discrete(name="Patient") +
scale_color_viridis(discrete = T, name = "patient")