Regeneration is rare in mammals, but mammalian species such spiny mice (Acomys spp.) can undergo this process. Evidence suggests that regeneration-competent organisms exhibit reduced inflammatory responses, such as lower numbers of inflammatory cells in circulation. This thesis explores a potential inflammation-regeneration trade-off by comparing the quantity and functionality of neutrophils in regeneration-competent (Acomys spp.) and -incompetent (Mus musculus) murids from varying environments. Results from this work suggest that regeneration-competent murids have nuanced differences in neutrophil quantity and function. Specifically, Acomys exhibit decreased neutrophil proportions in circulation and decreased proportions of mature neutrophil reserves in the bone marrow compared to Mus. Additionally, Acomys neutrophils can ingest more material than Mus neutrophils without altering bacteria-killing functions of neutrophils. However, bacterial killing by the serum alone was strongly enhanced in Acomys compared to Mus. Overall, this work suggests that Acomys utilize immunologic strategies that decrease inflammation without compromising pathogen defense.
