A note on the presence and sexual dimorphism of midventral glands in African spiny mice ( Acomys cahirinus )

Midventral skin glands secrete odors that mediate social contexts and are commonly found in rodents in the Cricetidae family rather than those in the Muridae family. African spiny mice (Acomys cahirinus) are rodents in the family Muridae known for their remarkable regenerative abilities, menstruation, tail osteoderms, and unique social behaviors, including cooperative breeding, communal parenting, and low aggression. They are also related to gerbils (Meriones), which are among the few murids that lack preputial glands and instead scent-mark with midventral glands. Acomys also lack preputial glands, but whether they have midventral glands is less well known. Here, we determined that Acomys have midventral glands near the umbilicus. As in Meriones, male Acomys had larger midventral glands that were visible after depilation. Immunohistochemistry showed that midventral glands in both sexes were positive for androgen receptors, suggesting they may be under androgen control. This investigation provides basic information on the presence, location, structure, and sexual dimorphism of the midventral glands in Acomys, providing a morphological baseline for comparative studies of social signaling across the Muridae family.