Meeting Abstract
Tissue turnover and remodeling has been an important focus of model system cell and developmental biology. Comparative approaches, mining the amazing diversity of invertebrate body plans, offer unique opportunities to gain insights into key elements of homeostasis and morphogenesis. We propose that the indirect developing enteropneust hemichordate worm Schizocardium californicum, with impressive regenerative capability and radical metamorphosis between larva and adult, provides a valuable opportunity for investigating remodeling and patterning during metamorphosis and regeneration. Cell turnover is a fundamental biological progress, a controlled cycle of cell death and cell birth that underlies homeostasis. However, little comparative data has been generated to investigate these key processes in less traditional systems. A window into this process of cell turnover is the metamorphosis of S. californicum in which we investigated the balance of proliferation and apoptosis during the dramatic remodeling of pre-existing structures, along with loss and gain of larval-specific and adult-specific traits respectively. The organization of complex body plans remains fascinating, and the remodeling and patterning that occurs during regeneration is an area of ongoing investigation. Regenerative capacities have been observed across the animal kingdom, but head or anterior regeneration had previously been attributed to only protostomes, not deuterostomes. The exception to this has been demonstrated in enteropneust hemichordates. We investigated the balance of proliferation and apoptosis during this process and anticipate that further studies in S. californicum will provide insights into the understanding of patterning programs used in anterior regeneration processes.
