Video talks on 16S data analysis posted.

URMAP ultra-fast read mapper posted (paper).

~20% of taxonomy annotations in SILVA and Greengenes are wrong (paper).

Taxonomy prediction is <50% accurate for 16S V4 sequences (paper).

97% OTU threshold is wrong for species, should be 99% for full-length 16S, 100% V4 (paper).

open reading frames

An open reading frame (ORF) is a segment of a nucleotide sequence that begins with a start codon, ends with a stop codon and is long enough to code for a protein. In USEARCH, the minimum number of amino acid codons in an ORF is set by the -mincodons option, default value 20.

With a nucleotide query sequence and amino acid database, USEARCH performs a translated search. ORFs are identified in the nucleotide sequence, and each ORF is treated as a separate query with its own termination conditions. This is because a single nucleotide sequence may span more than one gene.