Apoptosis and Tissue Regression in the Marine Sponge Microciona prolifera

A terminal deoxyribonucleotidyl transferase-mediated dUTP nick end label assay was conducted to investigate tissue regression and apoptosis in the cells of the marine sponge Microciona prolifera. The presence of apoptotic cell patterns were revealed through microscopic examinations of summer and winter sponges. The patterns may be affected by the combination of particle ingestion, generation of an adhesive proteoglycan and cell turnover for disposal of worn out cells.