Exposure to hypergravity during development leads to altered cartilage material properties and strain distribution in zebrafish.

Abstract

Terrestrial vertebrates have adapted to life on Earth and its constant gravitational field, which exerts load on the body and influences the structure and function of tissues. While the effects of microgravity on muscle and bone homeostasis are well described, the effects of shorter exposures to increased gravitational fields are less well characterized. Here, we exposed zebrafish to 3 and 6g hypergravity from 3-5 days post fertilisation, when key events in jaw cartilage morphogenesis occur. We did not observe changes to growth, or morphology of cartilage or muscle. However, we observed altered mechanical properties of jaw cartilages. We model the impact of these material property changes using Finite Element Analysis and show strain distribution in the jaw is altered following hypergravity. In regions of predicted altered strain we observed local changes to chondrocyte morphology, suggesting altered gravity affects chondrocyte maturation, ultimately leading to changes to cartilage structure and function.