get.seqs
The get.seqs command takes a list of sequence names (.accnos file) and either a fastq, fasta, name, group, list, count or align.report file to generate a new file that contains only the sequences in the list. This command may be used in conjunction with the list.seqs command to help screen a sequence collection. To complete this analysis, you need to download the folder compressed in the Esophagus.zip archive.
Options
To run get.seqs, you must provide the accnos option and at least one other option. The command will generate a *.pick.* file. To generate an accnos file, let’s first run unique.seqs, summary.seqs, screen.seqs, and list.seqs:
mothur > unique.seqs(fasta=esophagus.fasta)
mothur > summary.seqs(fasta=esophagus.unique.fasta)
Start End NBases Ambigs Polymer
Minimum: 1 831 831 0 4
2.5%-tile: 1 841 841 0 4
25%-tile: 1 857 857 0 5
Median: 1 866 866 0 5
75%-tile: 1 870 870 0 5
97.5%-tile: 1 900 900 5 7
Maximum: 1 1378 1378 20 8
# of Seqs: 656
mothur > screen.seqs(fasta=esophagus.unique.fasta, maxambig=0)
mothur > list.seqs(fasta=esophagus.unique.good.fasta)
This generates esophagus.unique.good.accnos, a file with 527 sequences.
A .accnos file is simply a list of file names that meets some given criterion (see list.seqs for further detail). If you have a subset of sequences that are of interest to you, and you want to retrieve them sequences from a larger .fasta file, another option for generating a .accnos file is to create your list (a single column of names) in a text editor or spreadsheet program that allows you to save your work as tab-delimited text. Notepad and Excel both allow you to do this, just be sure to use quotation marks around your file name in order to get your .accnos file type designation (e.g. “My_subset_sequences.accnos”).
accnos option
To use the accnos option, follow this example:
mothur > get.seqs(accnos=esophagus.unique.good.accnos, fasta=esophagus.fasta)
This generates the file esophagus.pick.fasta, which contains the following lines:
>9_1_12
GCAAGTCGAGGGGAAAC...
>9_1_14
GCAAGTCGAGGGGAACG...
>9_1_15
GCAAGTCGAGGGGAAAC...
...
fasta option
To use the fasta option, follow this example:
mothur > get.seqs(accnos=esophagus.unique.good.accnos, fasta=esophagus.fasta)
This generates the file esophagus.pick.fasta, which contains the sequences from esophagus.unique.good.accnos.
NOTE: You can enter multiple files separated by ‘-‘’s.
count option
The count file is similar to the name file in that it is used to represent the number of duplicate sequences for a given representative sequence. It can also contain group information.
mothur > get.seqs(accnos=esophagus.unique.good.accnos, count=esophagus.count_table)
NOTE: You can enter multiple files separated by ‘-‘’s.
alignreport option
To use the alignreport option, follow this example:
mothur > get.seqs(accnos=esophagus.unique.good.accnos, alignreport=esophagus.align.report)
This generates the file esophagus.pick.align.report, which contains the following lines:
QueryName QueryLength TemplateName TemplateLength SearchMethod SearchScore AlignmentMethod QueryStart QueryEnd TemplateStart TemplateEnd PairwiseAlignmentLength GapsInQuery GapsInTemplate LongestInsert SimBtwnQuery&Template
9_1_12 866 108139 1525 kmer 62.17 needleman 1 866 50 917 868 2 0 0 91.36
9_1_14 847 134265 1524 kmer 65.71 needleman 1 847 50 896 849 2 2 0 90.81
9_1_15 866 108139 1525 kmer 61.47 needleman 1 866 50 917 869 3 1 1 91.02
9_1_16 854 13820 1555 kmer 90.67 needleman 1 854 43 897 859 5 4 1 97.56
...
list option
To use the list option, follow this example:
mothur > get.seqs(accnos=esophagus.unique.good.accnos, list=esophagus.fn.list)
This generates the file esophagus.fn.pick.list, which contains the following lines:
unique 480 9_6_14,9_1_12 9_1_14 9_1_15 9_1_16 9_1_18 9_1_19 9_1_20 9_1_26 9_1_27 ...
0.00 265 9_4_14,9_7_28,9_1_26,9_6_14,9_1_12 9_2_20,9_1_14 9_1_15 9_1_16 ...
0.01 115 9_1_15,9_6_25,9_3_24,9_4_14,9_7_28,9_1_26,9_6_14,9_1_12 65_7_10,65_1_30,9_6_15,9_8_20, ...
...
NOTE: You can enter multiple files separated by ‘-‘’s.
taxonomy option
To use the taxonomy option, follow this example:
mothur > get.seqs(accnos=esophagus.unique.good.accnos, taxonomy=esophagus.silva.full.taxonomy)
This generates the file esophagus.silva.full.pick.taxonomy, which contains the following lines:
9_1_12 Bacteria(100);Bacteroidetes-Chlorobi(100);Bacteroidetes(100);Bacteroides-Prevotella(100);...
9_1_14 Bacteria(100);Bacteroidetes-Chlorobi(100);Bacteroidetes(100);Bacteroides-Prevotella(100);...
9_1_15 Bacteria(100);Bacteroidetes-Chlorobi(100);Bacteroidetes(100);Bacteroides-Prevotella(100);...
9_1_16 Bacteria(100);Firmicutes(100);Clostridia(100);Acidaminococcaceae(100);Veillonella(100);...
NOTE: You can enter multiple files separated by ‘-‘’s.
qfile option
The qfile option allows you to select sequences from your quality file, and can be used as follows:
mothur > get.seqs(accnos=esophagus.unique.good.accnos, qfile=esophagus.qual)
fastq option
The fastq option allows you to select sequences from your fastq file. You can enter multiple files separated by ‘-‘’s. This can be helpful when correcting file mismatches. For example if you have missing reads in your paired fastq files, try this:
mothur > list.seqs(fastq=test.R1.fastq-test.R2.fastq)
mothur > get.seqs(fastq=test.R1.fastq-test.R2.fastq, accnos=current)
contigsreport
The contigsreport option allows you to select sequences from your contigsreport file.
name - not recommended
The name option allows you to provide a name file.
We DO NOT recommend using the name file. Instead we recommend using a count file. The count file reduces the time and resources needed to process commands. It is a smaller file and can contain group information.
group - not recommended
The group parameter allows you to provide a group file.
We DO NOT recommend using the name / group file combination. Instead we recommend using a count file. The count file reduces the time and resources needed to process commands. It is a smaller file and can contain group information.
dups - not recommended
The dups parameter is only be used in tandem with a namefile. By default dups is true, so if any sequence in a specific line in the name file is in your .accnos file, then all sequences in that line will be kept. This is especially useful when used with the groupfile, since for most commands your files can contain only the unique sequences, but the groupfile need to contain all the sequences in your namefile. For example, let’s look at the following line from the esophagus.unique.good.accnos:
65_1_2 65_1_2,65_1_23,65_2_1,65_2_8
if dups is set to false, only 65_1_2 will be added to your files, but if dups is true, then 65_1_2,65_1_23,65_2_1,65_2_8 will all be added.
Revisions
- 1.28.0 Added count option
- 1.30.0 Bug Fix: dups=f could cause sequence name mismatches between new fasta and name files.
- 1.31.1 Bug Fix: dups=f, renaming issue, https://forum.mothur.org/viewtopic.php?f=3&t=2371
- 1.33.0 Added fastq option
- 1.37.0 Checks for repeat sequences names and eliminates them. Allows users creating their own templates to easily remove duplicate sequences from their reference files. #159
- 1.40.0 - Allow for () characters in taxonomy definitions. #350
- 1.44.0 - Adds contigsreport option. #660
- 1.47.0 Allows inputs to include multiple files. #803