Temperature effects on mitochondrial respiration of Protophormia terranovae and Musca domestica

• Published in: Insect biochemistry Vol. 10; no. 1; pp. 95 - 99
• Main Authors: Wood, Frederick E., Nordin, John H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1980
• Subjects: Musca domestica; low temperature stress; Protophormia terranovae; ADP; Q 10 values; oxidative phosphorylation; glycerol accumulation; respiratory states
• ISSN: 0020-1790
• DOI: 10.1016/0020-1790(80)90044-X

Oxygen electrode measurements of the respiratory activity of coupled mitochondria from adult Protophormia terranovae (which accumulates glycerol under cold stress) and Musca domestica (which does not) were conducted. Enthalpies of activation (-Ha's) were calculated from respiratory rate data obtained between +2°C and +26°C with sn-glycerol-3-phosphate as substrate. Both species have very similar — Ha's between +12°C and +26°C for respiratory states 3 and 4 and the uncoupled state. Below +11.5°C the enthalpy values for state 3 respiration increase 65% for P. terranovae and 122% for M. domestica while state 4 and uncoupled state rate values remain unchanged. These results demonstrate that since ADP requiring processes in oxidative phosphorylation become rate limiting for both species below +11.5°C they cannot regulate low temperature induced glycerol accumulation by P. terranovae. Calculations of Q 10 values through a series of temperature ranges indicate that, as expected, P. terranovae shows a greater facility for low temperature adaptation for state 3 oxidation than M. domestica.