Bridging the phenotypic gap: Real-time assessment of mitochondrial function and metabolism of the nematode Caenorhabditis elegans
Cristina Lagido, Jonathan Pettitt, Aileen Flett and L Anne Glover
Institute of Medical Sciences, School of Medical Sciences, University of Aberdeen, Aberdeen, UK
BMC Physiology 2008,
8:7. This is an Open Access article distributed under the terms of the Creative Commons Attribution License.
The ATP levels of an organism are an important physiological
parameter that is affected by genetic make up, ageing, stress and
We have generated luminescent C. elegans through ubiquitous, constitutive expression of firefly luciferase, widely used for in vitro ATP determination. We hypothesise that whole animal luminescence reflects its intracellular ATP levels in vivo. To test this, we characterised the bioluminescence response of C. elegans during
sublethal exposure to, and recovery from azide, a treatment that
inhibits mitochondrial respiration reversibly, and causes ATP
depletion. Consistent with our expectations, in vivo luminescence
decreased with increasing sublethal azide levels, and recovered fully
when worms were removed from azide. Firefly luciferase expression
levels, stability and activity did not influence the final
luminescence. Bioluminescence also reflected the lowered activity of
the electron transport chain achieved with RNA interference (RNAi) of
genes encoding respiratory chain components.
Results indicated that C. elegans luminescence reports on
ATP levels in real-time. For the first time, we are able to directly
assess the metabolism of a whole, living, multicellular organism by
determination of the relative ATP levels. This will enable genetic
analysis based on a readily quantifiable metabolic phenotype and will
provide novel insights into mechanisms of fitness and disease that are
likely to be of relevance for other organisms, as well as the worm.