Tag: Nucleotide BLAST (blastn)
An updated bacterial and archaeal representative genomes collection is available! We selected a total of 16,665 of the 262,000 prokaryotic assemblies in RefSeq to represent their respective species. For the first time, more complete assemblies (as calculated by CheckM) were ranked higher than less complete assemblies. See the ranked list of criteria for selecting representative assemblies here. Continue reading “Now available: Updated prokaryote representative genomes collection”
An updated bacterial and archaeal representative genomes collection is available! A total of 16,105 assemblies among the 249,000 prokaryotic assemblies in RefSeq were selected to represent their respective species. The collection has grown by 3.7% since January 2022. A total of 706 species are represented for the first time. In addition, 186 species are represented by a better assembly, and 124 species were removed because of changes in NCBI Taxonomy or uncertainty in their species assignment.
We updated the database on the Microbial Nucleotide BLAST page as well as the basic nucleotide BLAST RefSeq Representative genomes database (fourth in the menu) to reflect these changes. Finally, remember that you can now run BLAST searches against the proteins annotated on representative genomes (second in the menu). See more info here.
BLAST+ 2.13.0 includes several important new features including SRA BLAST programs, ARM Linux executables, and the ability to produce database metadata as well as some important improvements, and a few bug fixes. You can download the new BLAST release from the FTP site.
Beginning with this release, the BLAST distribution now includes the SRA BLAST programs blastn_vdb and tblastn_vdb that can directly search SRA and WGS projects without the need to build a BLAST database. See the BLAST documentation on how to use these programs with WGS projects.
This release also includes executables compiled under ARM Linux for the first time. Please let us know if you find any issues with ARM Linux programs.
Starting with BLAST+ 2.13.0, the makeblastdb program generates an additional file with the file extension .njs for nucleotide databases or .pjs for protein databases. These files contain BLAST database metadata in JSON format. See the BLAST database metadata section in the BLAST User Manual for an example. This file can be easily read by many tools and makes the BLAST database more compliant with FAIR principles.
See the release notes for more details on improvements and bug fixes for the release.
As we announced previously, BLAST can report limited usage information back to NCBI. This information shows us whether BLAST+ is being used by the community, and therefore is worth being maintained and developed. It also allows us to focus our development efforts on the most used aspects of BLAST+. Please help us improve BLAST by allowing BLAST to share information about your search. The BLAST privacy statement provides details on the information collected, how it is used, and how to opt-out of reporting if you don’t want to participate.
We are happy to announce an updated bacterial and archaeal representative genomes collection. The current collection contains a total of 15,507 assemblies selected from 236,000 prokaryotic RefSeq assemblies to represent their respective species. The collection has grown by five percent since August 2021. A total of 685 species are represented for the first time. In addition, 370 species are represented by a better assembly, and 84 species were removed because of changes in NCBI Taxonomy or uncertainty in their species assignment.
We updated the database on the Microbial Nucleotide BLAST page as well as the basic nucleotide BLAST RefSeq Representative genomes database (fourth in the menu) to reflect these changes. Finally, remember that you can now run BLAST searches against the proteins annotated on representative genomes (second in the menu). Find more information here.
The bacterial and archaeal representative genome collection has been updated! We selected a total of 14,912 of the 224,000 prokaryotic RefSeq assemblies to represent their respective species. The collection has grown by 8% since April 2021 and now includes Candidatus and endosymbiont species (Figure 1), which constitute 303 and 140 respectively of the 1,077 newly added species. In addition, 719 species are represented by a better assembly, and 70 species were removed because of changes in NCBI Taxonomy or uncertainty in their species assignment.
Figure 1. Graphical view of a portion of the RefSeq Representative assembly for the bedbug endosymbiont Candidatus Wolbachia massiliensis isolate PL13.
Continue reading “Updated prokaryotic representative genome collection”
BLAST+ 2.12.0 programs feature better multithreaded searches and support a different threading model, threading by query, that can be more efficient in some situations. The new release is also fully compatible the increase in the numeric range for the GI identifier, which will take effect in the nucleotide database later this year. The list below shows details of the new features and bug fixes. You can download the new BLAST release from the FTP site.
Continue reading “BLAST+ 2.12.0 now available with more efficient multithreaded searches”
We are happy to announce an updated bacterial and archaeal representative genome collection! We have selected 13,835 among 214,000 prokaryotic RefSeq assemblies to represent their respective species. The collection has increased by 6% since December 2020. About 950 species are represented for the first time, 476 species are represented by a better assembly, and 170 species were removed because of changes in NCBI Taxonomy or uncertainty in their species assignment.
Continue reading “Prokaryotic representative genomes update–over 900 new species!”
Join us on April 7, 2021 at 12PM eastern time to learn about new web BLAST and Primer-BLAST enhancements that improve your BLAST experience. You’ll also see a preview of some planned improvements to the databases that make it easier to find relevant matches.
Recent changes to web BLAST include added data columns on the descriptions table, so you can quickly find and sort your matches. Primer-BLAST now offers direct links from genome assembly pages, so you can easily select the specificity database. Primer-BLAST also now accepts multiple target templates making it easy to design primers that can amplify several similar sequences such as all splice variants of gene or the same target (16S, COI) from different strains or species.
After registering, you will receive a confirmation email with information about attending the webinar. A few days after the live presentation, you can view the recording on the NCBI webinars playlist on the NLM YouTube channel. You can learn about future webinars on the Webinars and Courses page.
We have updated the collection of representative genome assemblies for Bacteria and Archaea. As announced in April, this set is now recalculated three times a year. We selected a total of 11,727 prokaryotic assemblies to represent their respective species among the 192,000 assemblies in RefSeq. Six hundred and thirty-five species were included in the collection for the first time, while 395 organisms from undefined species (such as Bacillus bacterium) were removed. We were able to choose a higher-quality representative than in the previous set for 18% of Bacterial and Archaeal species due to improvements in the logic of the selection that is now based on the assembly length, number of pseudo CDSs called in the PGAP annotation, number of scaffolds, whether Gene IDs are available in the Gene database for the assembly that is currently representative, and type strain status. You can see the exact criteria in order of importance on the Prokaryotic RefSeq Genomes page. Now that the new selection process is in place, we expect future updates to have fewer changes. We will replace a representative only if the assembly has changed RefSeq status or if a substantially better assembly becomes available.
We have updated the database on the Microbial Nucleotide BLAST page as well as the basic nucleotide BLAST RefSeq Representative Genome Database, to reflect these changes.
You can download the reference and representative set from the Assembly resource. If you are interested in the annotation on these genomes, you can limit searches to proteins annotated on representative genomes by adding “refseq_select[filter]” to any query in the Protein database. For example, you can find all proteins annotated on representative genomes in the genus Klebsiella by using the query: “Klebsiella[organism] AND refseq_select[filter]“. A BLAST database of proteins annotated on representative genomes will be coming soon. Stay tuned!
We have a curated set of ribosomal RNA (rRNA) reference sequences (Targeted Loci) with verifiable organism sources and current names. This set is critical for correctly identifying and classifying prokaryotic (bacteria and archaea) and fungal samples (Table 1). To provide easy access to these sequences, we recently added a separate rRNA/ITS databases section on the nucleotide BLAST page for these targeted sequences that makes it convenient to quickly identify source organisms (Figure 1)
| Database | BioProjects | Sequences |
| 16S ribosomal RNA (Bacteria and Archaea) | PRJNA33317 , PRJNA33175
|
20,845 |
| 18S ribosomal RNA sequences (SSU) from Fungi type and reference material | PRJNA39195 | 2,337 |
| 28S ribosomal RNA sequences (LSU) from Fungi type and reference material | PRJNA51803 | 5,185 |
| Internal transcribed spacer region (ITS) from Fungi and Oomycete type and reference material | PRJNA177353, PRJNA362621
|
10,874 |
Table 1. NCBI curated targeted rRNA sequences now available as BLAST databases. Continue reading “New ribosomal RNA BLAST databases available on the web BLAST service and for download”