Sponsor
This work was supported by NSF grant DEB-0743871 (SE and DRD), PSU Faculty Enhancement Grant (SE), and PSU Undergraduate Scholarly and Creativity Grants (ACH and JK).
Published In
BMC Evolutionary Biology
Document Type
Article
Publication Date
1-1-2011
Subjects
Mitochondrial DNA, Caenorhabditis, Variation (Biology), Phenotype
Abstract
Background: Mutations that impair mitochondrial functioning are associated with a variety of metabolic and age-related disorders. A barrier to rigorous tests of the role of mitochondrial dysfunction in aging processes has been the lack of model systems with relevant, naturally occurring mitochondrial genetic variation. Toward the goal of developing such a model system, we studied natural variation in life history, metabolic, and aging phenotypes as it relates to levels of a naturally-occurring heteroplasmic mitochondrial ND5 deletion recently discovered to segregate among wild populations of the soil nematode, Caenorhabditis briggsae. The normal product of ND5 is a central component of the mitochondrial electron transport chain and integral to cellular energy metabolism. Results: We quantified significant variation among C. briggsae isolates for all phenotypes measured, only some of which was statistically associated with isolate-specific ND5 deletion frequency. We found that fecundity-related traits and pharyngeal pumping rate were strongly inversely related to ND5 deletion level and that C. briggsae isolates with high ND5 deletion levels experienced a tradeoff between early fecundity and lifespan. Conversely, oxidative stress resistance was only weakly associated with ND5 deletion level while ATP content was unrelated to deletion level. Finally, mean levels of reactive oxygen species measured in vivo showed a significant non-linear relationship with ND5 deletion level, a pattern that may be driven by among-isolate variation in antioxidant or other compensatory mechanisms. Conclusions: Our findings suggest that the ND5 deletion may adversely affect fitness and mitochondrial functioning while promoting aging in natural populations, and help to further establish this species as a useful model for explicit tests of hypotheses in aging biology and mitochondrial genetics.
DOI
10.1186/1471-2148-11-11
Persistent Identifier
http://archives.pdx.edu/ds/psu/7913
Citation Details
Estes, S., Coleman-Hulbert, A. L., Hicks, K. A., de Haan, G., Martha, S. R., Knapp, J. B., and ... Denver, D. R. (2011). Natural variation in life history and aging phenotypes is associated with mitochondrial DNA deletion frequency in Caenorhabditis briggsae. BMC Evolutionary Biology, 11(1), 1-8.
Table 1.
nd5-deletion-heteroplasmy-data.pdf (27 kB)
Table 2.
Description
Originally published in BMC Evolutionary Biology (http://www.biomedcentral.com/bmcevolbiol/) and can be found at (http://www.biomedcentral.com/1471-2148/11/11). This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.