Establishment of primmorphs from three Red Sea sponge species

Background Primmorphs are a special form of 3D-cell aggregates obtained from sponge cells. They can be used as biofermenters for the production of bioactive secondary metabolites. In the commercial development of sponge-derived drug leads, the production of primmorphs is one of the methods proposed to solve the supply problem. In addition, using primmorphs for the production of drugs can preserve the sponge population from extinction by producing enough quantities of the extracts and compounds that present in wild sponges.Objectives The presented work aimed to produce primmorphs of Red Sea sponges Hemimycale aff arabica, Stylissa carteri, and Crella (Yvesia) spinulata as long-term cultivation in vitro and identify the impact of different cell densities on their formation and growth.Results Microscopic studies suggested that primmorphs are formed through four stages: amorphous large cell floc within 1–3 h; small irregular cell aggregations in 1 day; large primary cell aggregations and round-shaped primmorphs after 3 days. Primmorphs of C. spinulata and S. carteri remained alive for 3–6 months. The primmorphs of H. arabica remained alive for 1 month. Long-term primmorph cultivation in vitro allows the creation of a controlled live model under experimental conditions.Conclusion This work may provide a solution to the ‘supply problem’ in the commercial development of sponge-derived drugs, as primmorphs can be used as biofermenters for bioactive secondary metabolite production. In addition, primmorphs can be used to study the morphogenesis of their sponges at different stages and transdifferentiation as well as the processes of spiculogenesis.