Int. J. Dev. Biol. 56: 183 - 191 (2012)
doi: 10.1387/ijdb.113485mp
© UBC Press

Physiological and molecular characterisation of cadmium stress in Schmidtea mediterranea

Michelle Plusquin*,1, An-Sofie Stevens1, Frank Van Belleghem1,2, Olivier Degheselle1, Andromeda Van Roten1, Jessica Vroonen1, Ronny Blust3, Ann Cuypers4, Tom Artois1 and Karen Smeets1

1Zoology: Biodiversity and Toxicology, Hasselt University, 2Open Universiteit Neder-land, School of Science, Heerlen, The Netherlands, 3Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Belgium and 4Environmental Biology, Hasselt University, Diepenbeek, Belgium

ABSTRACT The planarian Schmidtea mediterranea is a well-studied model organism for developmental research, because of its stem cell system. This characteristic also provides a unique opportunity to study stress management and the effect of stress on stem cells. In this study, we characterised the stress signature at different levels of biological organization. The carcinogenic metal cadmium was used as a model chemical stressor. We focused on stem cell activity and its interaction with other known stress parameters. Here, we have found that S. mediterranea is able to cope with high internal levels of cadmium. At endpoints such as size and mobility, cadmium-related stress effects were detected but all of these responses were transient. Correspondingly, cadmium exposure led to an elevated mitotic activity of the neob-lasts, at the same time points when the other responses disappeared. At the molecular level, we observed redox-related responses that can be linked with both repair as well as proliferation mechanisms. Together, our results suggest that these animals have a high plasticity. The induc-tion of stem cell activity may underlie this ‘restoring’ effect, although a carcinogenic outcome after longer exposure times cannot be excluded.

Keywords:

planaria, toxicology, stem cell, cadmium, gene expression

*Corresponding author e-mail: Michelle.plusquin@uhasselt.be