@article {KNZ001636,
	title = {Scraping the bottom of the barrel: are rare high throughput sequences artifacts?},
	journal = {Fungal Ecology},
	volume = {13},
	year = {2015},
	pages = {221 -225},
	abstract = {<p>Metabarcoding data generated using next-generation sequencing (NGS) technologies are overwhelmed with rare taxa and skewed in Operational Taxonomic Unit (OTU) frequencies comprised of few dominant taxa. Low frequency OTUs comprise a rare biosphere of singleton and doubleton OTUs, which may include many artifacts. We present an in-depth analysis of global singletons across sixteen NGS libraries representing different ribosomal RNA gene regions, NGS technologies and chemistries. Our data indicate that many singletons (average of 38 \% across gene regions) are likely artifacts or potential artifacts, but a large fraction can be assigned to lower taxonomic levels with very high bootstrap support (\&sim;32 \% of sequences to genus with \&ge;90 \% bootstrap cutoff). Further, many singletons clustered into rare OTUs from other datasets highlighting their overlap across datasets or the poor performance of clustering algorithms. These data emphasize a need for caution when discarding rare sequence data en masse: such practices may result in throwing the baby out with the bathwater, and underestimating the biodiversity. Yet, the rare sequences are unlikely to greatly affect ecological metrics. As a result, it may be prudent to err on the side of caution and omit rare OTUs prior to downstream analyses.</p>},
	keywords = {LTER-KNZ, fungi, High-throughput sequencing, Rare biosphere, Singleton},
	doi = {10.1016/j.funeco.2014.08.006},
	url = {https://www.sciencedirect.com/science/article/abs/pii/S1754504814001068?via\%3Dihub},
	author = {Brown, S.P. and Veach, A.M. and Rigdon-Huss, A.R. and Grond, K. and Lickteig, S.K. and Lothamer, K. and Oliver, A.K. and A. Jumpponen}
}
