Two preprints on DNA methylation were posted in bioRxiv. The first involves several different species and includes Peromyscus while the second is on Peromyscus exclusively Amin Haghani, Ake T Lu, Cae
A universal methylation clock was published. It involved almost 130 different species and Peromyscus was part of it. The study was led and coordinated by Steve Horvath from UCLA. Check here for detai