Physiological strategies in wild rodents: immune defenses of commensal rats

Abstract

The importance of issues associated with urban/commensal rats and mice (property damage, management costs, and health risks) press upon research on these animals. While the demography of commensal rodents is mostly studied, the need for understanding factors influencing their natural morbidity/mortality is also stressed. In this respect, more attention is expected to be paid to immunity, the physiological mechanism of defense against host survival threats (pathogens, parasites, diseases). Commensal rats and mice carry numerous pathogens that evoke diverse immune responses. The state of immunity in commensal house mice is studied in great detail, owing to the use of laboratory strains in biomedical research. Because commensal rats are, compared to mice, carriers of more zoonotic agents, rats' immunity is studied mainly in that context. Some of these zoonotic agents cause chronic, asymptomatic infections, which justified studies of immunological mechanisms of pathogen tolerance versus clearance regulation in rats. Occurrence of some infections in specific tissues/organs pressed upon analysis of local/regional immune responses and/or immunopathology. A survey of immunological activity/responses in commensal rats is given in this review, with mention of existing data in commensal mice. It should throw some light on the factors relevant to their morbidity and lifespan, supplementing the knowledge of commensal rodent ecology.

Recovery of small rodents from open‐pit marble mining: effects on communities, populations, and individuals

“…We predicted that after 10-13 years, rodent communities would have moved beyond the early pioneer phase of faunistic succession, and after more than 20-23 years, rodent communities would have recovered climax community structure (Jira et al 2013;Rozendaal et al 2019). Mechanistically, we predicted that longer after, or farther from, mining disturbance we would observe: (i) decreasing rodent community abundance, due to densitydependent competition and the re-establishment of a guild of rodent predators; resulting in (ii) reduced species' population abundance, in which individuals would exhibit (iii) poorer body condition, due to increasing competition and predation and a higher risk of parasitism (Doherty et al 2016;Mirkov et al 2023); with (iv) potential for altered body morphometry (Wu et al 2019), if novel succession trajectories in the recovering ecosystem (Hou et al 2019) result in environmental filtering, affecting species traits (Algar & López-Darias 2016) as rodents adapt to shifting ecological optima. In addition, we predicted that denser vegetation ground cover would promote small rodent abundance (Bush et al 2012).…”

Integrated Zoology’s collection of Wildlife Diseases Research Network

“…Mirkov et al. (2024) presented available knowledge on the state of immunity of commensal rats. Characteristics of innate immunity and inflammation (systemic or tissue) in response to environmental stimuli, as well as data showing signs of activities with the capacity of inflammation counteracting are documented.…”

“…In this issue, Integrative Zoology publishes a special subsection "Infection, immunity and health of animals" for the Zoonotic Disease Coordination Network. Mirkov et al (2024) presented available knowledge on the state of immunity of commensal rats. Characteristics of innate immunity and inflammation (systemic or tissue) in response to environmental stimuli, as well as data showing signs of activities with the capacity of inflammation counteracting are documented.…”