Extended Data Fig. 4: Features of vOTUs versus non-viral sequence clusters within data.
From: Expanding known viral diversity in the healthy infant gut
Distribution of size, MRA and sample prevalence for contaminant non-viral sequence clusters and curated vOTUs respectively. The vOTU size distribution shows peaks corresponding to genome lengths for the three major classes of viruses in the dataset, namely anelloviruses, microviruses and caudoviruses (3 kb, 5.5 kb, and 40 kb). The contaminant size distribution peaks at the contig inclusion cutoff (1 kb) continuing with a long uniform tail, consistent with the unspecific origin expected for contaminating DNA. Curated vOTUs were more abundant and prevalent than contaminating species. The majority of the contaminating sequences were sample-specific, in contrast to most curated vOTUs which were found in more than one sample. The latter is consistent with their bacterial chromosomal origin, as unspecific subsampling of the large bacterial genome space is unlikely to yield overlaps between samples.
