Document Type

Article

Publication Date

3-2017

Department

Biology

Abstract

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 metabolism with new data on mitochondrial bioenergetics across the temperature range 14°–42°C. Across this range, our measure of mitochondrial efficiency closely paralleled larval growth rates. At supraoptimal temperatures for growth, mitochondrial efficiency was reduced, which could explain the mismatch between growth and metabolism observed at the whole-organism level.

Comments

Copyright 2017 by The University of Chicago. All rights reserved.

Original Publication Information

Martinez, Eloy, Michael A. Menze, and Salvatore J. Agosta. "Reduced Mitochondrial Efficiency Explains Mismatched Growth and Metabolic Rate at Supraoptimal Temperatures." 2017. Physiological and Biochemical Zoology 90(2): 294-298.

DOI

10.1086/689871

Available for download on Thursday, March 01, 2018

Included in

Biology Commons

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