We have made updates to the Rattus norvegicus (Norway rat) gene annotation. The GRCr8 assembly is now the reference and mRatBN7.2 has been enhanced with manual annotation.
GRCr8 is now the reference
We are excited to announce the release of the Ensembl automated annotation for the latest Rattus norvegicus (Norway rat) reference assembly from the Genome Reference Consortium (GRC)! The new assembly, GRCr8 (GCA_036323735.1), which became available in January 2024 will replace the current mRatBN7.2 (GCA_015227675.2) as the new reference assembly for this species.
The latest genome, which is now available in Ensembl Rapid Release, was annotated via the Ensembl automated annotation system. More details on the annotation can be found via our Rapid Release documentation.
mRatBN7.2 has been enhanced with manual annotation
Additionally, the previous assembly, mRatBN7.2 (GCA_015227675.2) has been significantly enhanced with manual annotation by the HAVANA team. The updated annotation has become available in Ensembl Rapid Release 62.
The HAVANA team meticulously manually updated the annotation of over 200 community-selected genes, corrected automatic annotation errors, such as incorrect splicing and incomplete transcripts, and expanded isoforms using long-read RNA-seq data. The entire major histocompatibility complex (MHC) region was manually updated creating an additional 38 new genes in this region. This manual enrichment has ensured higher accuracy and completeness, which is essential for advanced genomic studies.
Future Goals
The GRCr8 assembly currently features automatic annotation, primarily aimed at generating a conservative set of protein-coding gene models, with non-coding genes and pseudogenes also annotated. Looking ahead, a manually updated annotation of the GRCr8 assembly will be available soon. Manual annotation from mRatBN7.2 will be projected onto GRCr8 with additional isoforms incorporated from long-read RNA-seq data on Ensembl. We hope that this will provide the scientific community with a more accurate tool for advancing research and understanding of the R. norvegicus genome.
Stay tuned for further updates on our blog!
Authors: Francesca Tricomi and Jose Gonzalez
Editors: Leanne Haggerty and Louisse Paola Mirabueno