Issue 7, 2015

MtHc: a motif-based hierarchical method for clustering massive 16S rRNA sequences into OTUs

Abstract

The recent sequencing revolution driven by high-throughput technologies has led to rapid accumulation of 16S rRNA sequences for microbial communities. Clustering short sequences into operational taxonomic units (OTUs) is an initial crucial process in analyzing metagenomic data. Although many methods have been proposed for OTU inferences, a major challenge is the balance between inference accuracy and computational efficiency. To address these challenges, we present a novel motif-based hierarchical method (namely MtHc) for clustering massive 16S rRNA sequences into OTUs with high clustering accuracy and low memory usage. Suppose all the 16S rRNA sequences can be used to construct a complete weighted network, where sequences are viewed as nodes, each pair of sequences is connected by an imaginary edge, and the distance of a pair of sequences represents the weight of the edge. MtHc consists of three main phrases. First, heuristically search the motif that is defined as n-node sub-graph (in the present study, n = 3, 4, 5), in which the distance between any two nodes is less than a threshold. Second, use the motif as a seed to form candidate clusters by computing the distances of other sequences with the motif. Finally, hierarchically merge the candidate clusters to generate the OTUs by only calculating the distances of motifs between two clusters. Compared with the existing methods on several simulated and real-life metagenomic datasets, we demonstrate that MtHc has higher clustering performance, less memory usage and robustness for setting parameters, and that it is more effective to handle the large-scale metagenomic datasets. The MtHC software can be freely download from http://compgenomics.utsa.edu/mthc/ for academic users.

Graphical abstract: MtHc: a motif-based hierarchical method for clustering massive 16S rRNA sequences into OTUs

Article information

Article type
Paper
Submitted
30 Jan 2015
Accepted
14 Apr 2015
First published
14 Apr 2015

Mol. BioSyst., 2015,11, 1907-1913

MtHc: a motif-based hierarchical method for clustering massive 16S rRNA sequences into OTUs

Z. Wei and S. Zhang, Mol. BioSyst., 2015, 11, 1907 DOI: 10.1039/C5MB00089K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements