Thermophilic\nBehavior of Heat-Dissociative Coacervate\nDroplets

In\nexploring the genesis of life, liquid–liquid phase-separated\ncoacervate droplets have been proposed as primitive protocells. Within\nthe hydrothermal hypothesis, these droplets would emerge from molecule-rich\nhot fluids and thus be subjected to temperature gradients. Investigating\ntheir thermophoretic behavior can provide insights into protocell\nfootprints in thermal landscapes, advancing our understanding of life’s\norigins. Here, we report the thermophilic behavior of heat-dissociative\ndroplets, contrary to the intuition that heat-associative condensates\nwould prefer hotter areas. This aspect implies the preferential presence\nof heat-dissociative primordial condensates near hydrothermal environments,\nfacilitating molecular incorporation and biochemical syntheses. Additionally,\nour investigations reveal similarities between thermophoretic and\nelectrophoretic motions, dictated by molecular redistribution within\ndroplets due to their fluid nature, which necessitates revising current\nelectrophoresis frameworks for surface charge characterization. Our\nstudy elucidates how coacervate droplets navigate thermal and electric\nfields, reveals their thermal-landscape-dependent molecular characteristics,\nand bridges foundational theories of early life: the hydrothermal\nand condensate-as-protocell hypotheses.