Please use this identifier to cite or link to this item: https://hdl.handle.net/2440/73882
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Type: Journal article
Title: A test of the oxidative damage hypothesis for discontinuous gas exchange in the locust Locusta migratoria
Author: Matthews, P.
Snelling, E.
Seymour, R.
White, C.
Citation: Biology Letters, 2012; 8(4):682-684
Publisher: The Royal Society
Issue Date: 2012
ISSN: 1744-9561
1744-957X
Statement of
Responsibility: 
Philip G.D. Matthews, Edward P. Snelling, Roger S. Seymour and Craig R. White
Abstract: The discontinuous gas exchange cycle (DGC) is a breathing pattern displayed by many insects, characterized by periodic breath-holding and intermittently low tracheal O2 levels. It has been hypothesized that the adaptive value of DGCs is to reduce oxidative damage, with low tracheal O2 partial pressures (PO2 ∼2–5kPa) occurring to reduce the production of oxygen free radicals. If this is so, insects displayingDGCs should continue to actively defend a low tracheal PO2 even when breathing higher than atmospheric levels of oxygen (hyperoxia). This behaviour has been observed in moth pupae exposed to ambient PO2 up to 50 kPa. To test this observation in adult insects, we implanted fibre-optic oxygen optodes within the tracheal systems of adult migratory locusts Locusta migratoria exposed to normoxia, hypoxia and hyperoxia. In normoxic and hypoxic atmospheres, the minimum tracheal PO2 that occurred during DGCs varied between 3.4 and 1.2 kPa. In hyperoxia up to 40.5 kPa,the minimum tracheal PO2 achieved during a DGC exceeded 30 kPa, increasing with ambient levels. These results are consistent with a respiratory control mechanism that functions to satisfy O2 requirements by maintaining PO2 above a critical level, not defend against high levels of O2.
Keywords: Discontinuous gas exchange
insect
hyperoxia
Rights: © 2012 The Royal Society
DOI: 10.1098/rsbl.2012.0137
Grant ID: http://purl.org/au-research/grants/arc/DP0879605
Appears in Collections:Aurora harvest
Earth and Environmental Sciences publications

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