Potential use of brush-tailed mice for evolutionary developmental biology studies: Calomyscus elburzensis as an appropriate rodent model

Rodents (mainly mice and rats) are the most commonly used animal models for studies of cancer biology, immunology, genetics, developmental biology and also embryo transfer techniques in domestic and endangered animal species, and even in humans. Herein, we aimed to evaluate Goodwin’s brush-tailed mouse (Calomyscus elburzensis) as a suggested model species for evolutionary developmental biology (Evo-Devo) studies. Trapping procedure was performed in Khaje-Morad rocky region, south center of Mashhad, Razavi Khorasan province, Iran between April and September 2014. Breeding procedure for 15 adult females and 12 adult males was conducted in captivity between 2014 and 2017. Brother × sister mating in each generation was used as laboratory rearing method for breeding three generations (F1-F3). The average of pregnancy period and the differences in the sex of newborns in different parturition were measured using descriptive statistical analyses (independent-sample t-test). We observed that Goodwin’s brush-tailed mice were relatively social rodents, and due to their high level of tolerance in harsh conditions, no hibernation, low cost, small size, the potential to be bred all round the year, nearly short pregnancy period (about 4.5 weeks) and long lifespan in captivity (generally between 4 to 5 years) have the potential to be bred and used in different fields of evolutionary studies. However, low reproductive output (known up to five till now) and late sexual maturity (at about four months) as compared with Mus and Rattus, are some drawbacks associated with Calomyscus, which might be improved by gradual genetic changes and artificial selection.