Quantitative imaging of Caenorhabditis elegans dauer larvae during cryptobiotic transition using optical diffraction tomography

Abstract

Caenorhabditis elegans can survive upon harsh environments by entering dauer diapause with reduced metabolic activity and distinctive structural changes. We employed optical diffraction tomography (ODT) to quantitatively measure the transition of mass density distribution of living C. elegans larvae in the reproductive and diapause stages. ODT revealed that the mass density of C. elegans larvae increased upon entry into dauer diapause, and surprisingly, the harshly desiccated dauer larvae exhibited very high refractive index values (n ~ 1.5). Moreover, mutants that are sensitive to desiccation displayed structural abnormalities in the anhydrobiotic stage that were not observed by conventional microscopy.