You can find the mRatNor1.1 assembly at ftp://ftp.sanger.ac.uk/pub/users/kj2/Darwin.
The files are: mRatNor1_1.curated_primary.20200424.fa
containing the primary assembly. The scaffold names need to be translated using
mRatNor1_1.chromosome.list.csv
where the entries refer to <scaffold_name>,<chr_name>,<yes if it’s the main part of the chromosome/no if it’s an unlocalised part of the chromosome>
mRatNor1_1.all_haplotigs.20200424.fa
Contains the alternative assembly.
CAVEAT: This is the current assembly not yet submitted to INSDC and therefore liable to change if the pending marker analysis points out any remaining errors.
Happy analysing, please let us know if you find any issues!