We compared non-shivering thermogenesis between two adjacent populations of the common spiny mouse Acomys cahirinus from different habitats, in relation to increasing salinity. Individuals were captured from the north- and south-facing slopes of the same valley, that represent "Mediterranean" and "desert" habitats, respectively. We hypothesized that the two populations of mice would differ in their thermoregulatory capacities, reflecting their need to cope with the environmental stress in each habitat. We measured resting metabolic rate by recording oxygen consumption, body temperature and response to an injection of exogenous noradrenaline. Mice were maintained on diets with increasing levels of salt intake to examine their abilities to cope with increasing osmotic stress. Mice from north-facing slopes generally had a higher resting metabolic rate and a higher increase in oxygen consumption in response to noradrenaline than mice from south-facing slopes. Increasing salinity decreased resting metabolic rate values, body temperature, and oxygen consumption in response to noradrenaline in both populations, and diminished slope-dependant differences. We suggest that these differences could be a result of an ongoing adaptive process to different climatic conditions, typical of the Mediterranean region, that are a demonstrable example of evolution in action.
|Number of pages||5|
|Journal||Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology|
|State||Published - 2002|
Bibliographical noteFunding Information:
Acknowledgements We would like to thank Hagai Kupstein, Alina Neuman and Udi Ron for their assistance in the field and lab. The manuscript has benefited greatly from the helpful comments of two anonymous referees. This work was supported by a grant from the Israel Science Foundation, Israel Academy of Science and Humanities to AH and DA (grant no. 298/97-2).
- Non-shivering thermogenesis
- Resting metabolic rate
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology