RefSeq release 237 is now available online and from the FTP site! You can access RefSeq data through NCBI Datasets. The release is provided in several directories as a complete dataset and also as divided by logical groupings.    

What’s included in this release?  

As of August 31, 2026, this full release incorporates genomic, transcript, and protein data containing:

• 645,505,406 records 
• 495,290,394 proteins 
• 86,067,871 RNAs 
• Sequences from 184,752 organisms 

New full annotations are available for Rattus norvegicus, including two full assemblies:

• Rat GRCr8 (strain: BN/NHsdMcwi; reference genome): GCF_036323735.1-RS_2026_08 
• Rat SHRSP_T2T (strain: SHRSP/BbbUtx): GCF_021556685.1-RS_2026_08

These annotations incorporate:

• Human expert curation improvements for over 4,000 genes and 17,000 transcript models
• Automated annotation based on the latest EGAP software, integrating 96 runs of RNA-seq, 50 runs of CAGE, and over 300 million IsoSeq and ONT reads

Quality highlights:

• BUSCO analysis of the proteins shows the annotations are over 99.3% complete
• Over 85% of annotated transcripts are supported by a transcript spanning the complete splice structure

The above metrics mean these annotations are some of the highest quality available in RefSeq today!

Access the annotations:

• NCBI Datasets 
• Genome Data Viewer (GDV) 
• Comparative Genome Viewer (CGV) 
• BLAST 
• FTP

RefSeq has added Candidozyma auris strain B8441 (GCF_002759435.1, Clade I) alongside the existing type material strain B11220 (GCF_003013715.1, Clade II). Strain B8441 is widely used as the reference for Clade I, which represents the virulent, drug-resistant members of this species.

This release contains new or updated annotations generated by NCBI’s eukaryotic genome annotation pipeline for 63 species, including:

• Gelada, based on new assembly ASM4086918v1 (GCF_040869185.1-RS_2026_07) 
• Ryukyu mouse, based on new assembly Mus_caroli_1 (GCF_978045245.1-RS_2026_07) 
• Domestic yak, based on new T2T assembly Bosgru_T2T1.0 (GCF_055505025.1-RS_2026_07) 
• Blue tit, based on new assembly bCyaCae1.hap1.1 (GCF_971803275.1-RS_2026_06) 
• Vinegar fly (Drosophila serrata), based on new assembly ASM3504612v1 (GCF_035046125.1-RS_2026_08) 
• Alfalfa plant (Medicago sativa), based on new assembly Bolivia_mono (GCF_051527215.1-RS_2026_07)  

RefSeq is exploring criteria for reducing the number of genomes included in the dataset for frequently sequenced prokaryote species such as Escherichia coli. If you’re using large sets of RefSeq prokaryote genomes for a task that may be impacted by such a change, either positively or negatively, please contact us.

RefSeq is part of the NIH Comparative Genomics Resource (CGR). CGR facilitates reliable comparative genomics analyses for all eukaryotic organisms through an NCBI Toolkit and community collaboration.

Please reach out to us if you have questions or would like to provide feedback!