Fagre, A. et al. Plos Pathog 17, e1009585 (2021)

Laboratory mice of the mus musculus variety aren’t naturally susceptible to SARS-CoV-2 infection, which relies on ACE2 as its point of entry into hosts. Other members of the rodent family, however, can be infected with the virus; these species include Syrian golden hamsters and, per new research from Colorado State University, deer mice.

Peromyscus maniculatus, which can be found throughout North America, have 17 of the 20 ACE2 residues considered critical for SARS-CoV-2 binding, suggesting they might be susceptible to infection. To confirm, the team experimentally challenged animals of both sexes. They found viral particles in the lungs and brains of the mice as well as elevated expression of genes involved with immune responses. Infected deer mice could also transmit the virus to naïve conspecifics. The results suggest deer mice could serve as an additional rodent model of SARS-CoV-2 infection, while also raising concerns about a novel reservoir should the virus spill back into wild populations.