Using the Carnivorous Sponge Lycopodina hypogea as a Nonclassical Model for Understanding Apoptosis-Mediated Shape Homeostasis at the Organism Level

The dynamic equilibrium between death and regeneration is well established at the cell level. Conversely, no study has investigated homeostatic control of shape whole organism level through processes involving apoptosis. To address this fundamental biological question, we took advantage morphological functional properties carnivorous sponge Lycopodina hypogea. During its feeding cycle, undergoes spectacular changes. Starved animals display many elongated filaments to capture prey. After capture, prey are digested in absence any centralized digestive structure. Strikingly, actively regress reform maintain a constant, homeostatically controlled number size resting sponges. This unusual mode nutrition provides unique opportunity better understand involved renewal adult tissues. Throughout these processes, proliferation apoptosis interconnected key actors. Therefore, L. hypogea an ideal how molecular cellular mechanistically coupled ensure global homeostasis.