Open Access. Powered by Scholars. Published by Universities.®

Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Series

Temperature

University of Louisville

Publication Year

Articles 1 - 3 of 3

Full-Text Articles in Biology

Reduced Mitochondrial Efficiency Explains Mismatched Growth And Metabolic Rate At Supraoptimal Temperatures., Eloy Martinez, Michael A. Menze, Salvatore J. Agosta Mar 2017

Reduced Mitochondrial Efficiency Explains Mismatched Growth And Metabolic Rate At Supraoptimal Temperatures., Eloy Martinez, Michael A. Menze, Salvatore J. Agosta

Faculty Scholarship

The relationship between whole-organism growth and metabolism is generally assumed to be positive and causative; higher metabolic rates support higher growth rates. In Manduca sexta, existing data demonstrate a deviation from this simple prediction: at supraoptimal temperatures for larval growth, metabolic rate keeps increasing while growth rate is decreasing. This mismatch presumably reflects the rising “cost of maintenance” with temperature. Precisely what constitutes this cost is not clear, but we suspect the efficiency with which mitochondria harness oxygen and organic substrates into cellular energy (ATP) is key. We tested this by integrating existing data on M. sexta growth and …


Tradeoffs Of Warm Adaptation In Aquatic Ectotherms : Live Fast, Die Young?, A. Porreca, E. Martinez, R. Colombo, Michael Menze Aug 2015

Tradeoffs Of Warm Adaptation In Aquatic Ectotherms : Live Fast, Die Young?, A. Porreca, E. Martinez, R. Colombo, Michael Menze

Faculty Scholarship

In the face of a changing climate, questions regarding sub-lethal effects of elevated habitat temperature on the physiology of ectotherms remain unanswered. In particular, long-term responses of ectotherms to the warming trend in tropical regions are unknown and significantly understudied due primarily to the difficulties in specimen and community traceability. In freshwater lakes employed as cooling reservoirs for power plants, increased physiological stress from high water temperature can lead to an increase in mortality, reduce growth, and potentially alter the community structure of fishes. Throughout this study, we employ this highly tractable system to assess how elevated thermal regimes can …


Physiological Performance Of Warm-Adapted Marine Ectotherms : Thermal Limits Of Mitochondrial Energy Transduction Efficiency., Eloy Martinez, Eric Hendricks, Michael Menze, Joseph Torres Aug 2015

Physiological Performance Of Warm-Adapted Marine Ectotherms : Thermal Limits Of Mitochondrial Energy Transduction Efficiency., Eloy Martinez, Eric Hendricks, Michael Menze, Joseph Torres

Faculty Scholarship

Thermal regimes in aquatic systems have profound implications for the physiology of ectotherms. In particular, the effect of elevated temperatures on mitochondrial energy transduction (i.e. energy from carbon substrates to ATP) in tropical and subtropical teleosts may have profound consequences on organismal performance and population viability. Upper and lower whole-organism critical temperatures for teleosts suggest that subtropical and tropical species are not susceptible to the warming trends associated with climate change, but sub-lethal effects on energy transduction efficiency and population dynamics remain unclear. The goal of the present study was to compare the thermal sensitivity of processes associated with mitochondrial …