2/15/2024 – Announcing the release of GRCr8: A new rat reference assembly!

GRCr8 (GenBank NCBI # GCA_036323735.1) is the latest version of the rat reference genome assembly, an evolution of mRatBN7.2. This assembly incorporates optical mapping, chromosomal conformation capture (Hi-C), and PacBio HiFi sequencing data. Per the Genome Reference Consortium (GRC) blog the assembly was gap filled using contigs from the PacBio CLR reads produced for mRatBN7.2. Additional short read genomic sequence from a BN/NHsdMcwi rat in the Hybrid Rat Diversity Program at the Medical College of Wisconsin was used for assembly polishing. The genome size increased, largely because of improvement in the structure of some genomic regions, in particular chrY. This assembly will be annotated by groups such as RefSeq/ NCBI and Ensembl for gene models, mapping positions and locations of genes, introns/exons structure, and other genomic elements. As data becomes available for this assembly it will be integrated into genome browsers at various resources, such as the Rat Genome Database JBrowse 2.