1
|
Williams CM, Rocca JR, Edison AS, Allison DB, Morgan TJ, Hahn DA. Cold adaptation does not alter ATP homeostasis during cold exposure in Drosophila melanogaster. Integr Zool 2019; 13:471-481. [PMID: 29722155 DOI: 10.1111/1749-4877.12326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In insects and other ectotherms, cold temperatures cause a coma resulting from loss of neuromuscular function, during which ionic and metabolic homeostasis are progressively lost. Cold adaptation improves homeostasis during cold exposure, but the ultimate targets of selection are still an open question. Cold acclimation and adaptation remodels mitochondrial metabolism in insects, suggesting that aerobic energy production during cold exposure could be a target of selection. Here, we test the hypothesis that cold adaptation improves the ability to maintain rates of aerobic energy production during cold exposure by using 31 P NMR on live flies. Using lines of Drosophila melanogaster artificially selected for fast and slow recovery from a cold coma, we show that cold exposure does not lower ATP levels and that cold adaptation does not alter aerobic ATP production during cold exposure. Cold-hardy and cold-susceptible lines both experienced a brief transition to anaerobic metabolism during cooling, but this was rapidly reversed during cold exposure, suggesting that oxidative phosphorylation was sufficient to meet energy demands below the critical thermal minimum, even in cold-susceptible flies. We thus reject the hypothesis that performance under mild low temperatures is set by aerobic ATP supply limitations in D. melanogaster, excluding oxygen and capacity limitation as a weak link in energy supply. This work suggests that the modulations to mitochondrial metabolism resulting from cold acclimation or adaptation may arise from selection on a biosynthetic product(s) of those pathways rather than selection on ATP supply during cold exposure.
Collapse
Affiliation(s)
- Caroline M Williams
- Department of Integrative Biology, University of California, Berkeley, California, USA.,Departments of Entomology and Nematology, University of Florida, Gainesville, Florida, USA
| | - James R Rocca
- Advanced Magnetic Resonance Imaging and Spectroscopy Facility, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Arthur S Edison
- Departments of Entomology and Biochemistry, University of Florida, Gainesville, Florida, USA.,Departments of Genetics and Biochemistry, Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - David B Allison
- Department of Epidemiology and Biostatistics, School of Public Health, Indiana University Bloomington, Bloomington, Indiana, USA
| | - Theodore J Morgan
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Daniel A Hahn
- Departments of Entomology and Nematology, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
2
|
Thompson S. NMR spectroscopy: Its basis, biological application and use in studies of insect metabolism. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0020-1790(90)90039-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|