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).

blast6out file

The blast6out option specifies an output file in a format compatible with the NCBI BLAST -m8 and NCBI BLAST+ -outfmt 6 formats. It is a tab-separated text file with one line per alignment. By convention I use the .b6 extension for files in this format. There are twelve fields, as shown in the table.

Field		Description
1		Query label.
2		Target (database sequence or cluster centroid) label.
3		Percent identity.
4		Alignment length.
5		Number of mismatches.
6		Number of gap opens.
7		Start position in query. Query coordinates start with 1 at the first base in the sequence as it appears in the input file. For translated searches (nucleotide queries, protein targets), query start<end for +ve frame and start>end for -ve frame.
8		End position in query.
9		Start position in target. Target coordinates start with 1 at the first base in sequence as it appears in the database. For untranslated nucleotide searches, target start<end for plus strand, start>end for a reverse-complement alignment.
10		End position in target.
11		E-value calculated using Karlin-Altschul statistics.
12		Bit score calculated using Karlin-Altschul statistics.