The contractile vacuole (CV) is a poorly studied organelle involved in osmotic regulation. In every contraction cycle, the CV expels excess liquid to maintain osmoregulation. CVs are found in single-celled eukaryotes including parasitic and free-living ciliates. Parasitic examples include Trypanosoma cruzi, amoebas, and Leishmania parasites. We use the free-living ciliate Vorticella convallaria as a model for CV cycling, which can be observed directly under a microscope. The CV contraction rate in Vorticella convallaria, increases with temperature within physiologically relevant non-lethal temperature ranges. We performed a historical literature review of CV cycling rates and temperature across ciliates and amoeba. The Arrhenius equation was used to calculate the activation energy barrier for CV contraction. The slope of the Arrhenius graph was similar across all organisms ranging from 6000 to 17000 calories (per mol CV cycle), suggesting that conserved chemical or physical processes control CV cycling across biology. Future research will investigate whether using drugs to inhibit the CV will change the slope of the Arrhenius graph in Vorticella convallaria, and whether those same drugs will exacerbate osmotic cell death in the parasite Crithidia fasciculata. Ultimately, our results may contribute to the development of anti-parasitic drugs targeting parasites’ unique CV organelle.
Support or Funding Information
Albright College and Chemistry and Biochemistry Department start-up funding and PA Academy of Sciences Undergraduate Research Grant
