Using a non-model organism for studying marsupial hibernation: the monito del monte (Dromiciops gliroides) from southern South America

Hibernation is a remarkable energy-saving strategy that enables mammals to survive extended periods of cold and food scarcity by drastically reducing their metabolic rate, core body temperature, and overall physiological activity. This phenomenon has been thoroughly investigated in placental (eutherian) mammals, particularly rodents and bats, which serve as classical models. However, our understanding of hibernation across the broader mammalian phylogeny remains incomplete, with marsupials being notably underrepresented despite their key evolutionary position. Here, I introduce our hibernation research in Dromiciops gliroides, a small arboreal marsupial endemic to the temperate rainforests of southern Chile and Argentina. As the only living representative of the order Microbiotheria, Dromiciops holds a pivotal phylogenetic position as the closest South American relative to Australian marsupials, offering a unique opportunity to examine the early evolutionary origins of heterothermy in mammals. Our integrative approach combines field and laboratory data, including high-resolution body temperature data-logging, open-flow respirometry, and molecular assays targeting genes involved in thermogenesis and metabolic suppression. We document prolonged torpor bouts during winter, with body temperatures approaching ambient and metabolic rates suppressed by more than 95%. These patterns satisfy strict physiological criteria for hibernation and mirror the depth of torpor observed in classical eutherian models. Importantly, torpor in Dromiciops is modulated by environmental cues, supporting the idea that this capacity is both conserved and phenotypically plastic among mammals. Beyond its ecological and evolutionary relevance, Dromiciops physiology serves as a conceptual model for biomedical applications. Inspired by its metabolic suppression strategies, we are planning to develop an ex-situ liver perfusion protocol in which a "hibernation cocktail” (targeting AMPK, mTOR, and cellular stress pathways) is used to induce reversible metabolic depression in grafts—offering translational promise for extending organ preservation and improving transplant viability.