EAPSI: Understanding How Temperature Affects Liver Function in Plant-Eating Marsupials

Kurnath Patrice, Salt Lake City UT

Investigators

Abstract

At every meal, herbivores deal with toxins produced as a defense by plants. Work from pharmacology and agriculture suggests this toxicity increases with rising ambient temperatures. Known as temperature-dependent toxicity (TDT), this phenomenon is the likely result of decreased liver function by mammals at warmer temperatures. If TDT is also relevant to mammalian herbivores, then these mammals could be negatively impacted in a warming environment. To date, TDT has only been studied in a single natural system with wild, plant-eating rodents. The current project will expand the investigation of TDT to include a new species (with interesting comparative properties) that is found only in Australia. In collaboration with Dr. William Foley at the Australian National University, an expert in the field of plant-mammal interactions, this project will test the effect of temperature on liver function in the common brushtail possum (Trichosurus vulpecula). Due to global change, increases in ambient temperature are a novel threat for herbivorous mammals. This project will provide an experimental model to estimate the ability of common brushtail possums to balance thermoregulation and plant toxin metabolism with changes in ambient temperature. Whole-organisms assays of liver function will be conducted in a temperature-controlled, laboratory setting. Brushtail possums are marsupials that vary greatly in body size and class of dietary toxins compared to previous TDT work in small rodents. The interaction between temperature and plant toxins could greatly impact the feeding strategies and diet selection for free-ranging mammalian herbivores, which are crucial components of many ecosystems. A more detailed understanding of TDT will not only advance the field of plant-animal interactions, but will also enable more accurate predictions of mammalian species? responses to global change. This NSF EAPSI award will be funded in collaboration with the Australian Academy of Science.