ИСТИНА

Sponges are the most ancient multicellular animals. They demonstrate broad recovery abilities after various wounds, and due to their phylogenetic position, studies of repair processes in sponges are required for understanding the evolution of the regeneration mechanisms in animals. We studied the reparative regeneration in two widely distributed species of the White Sea calcareous sponges with an asconoid aquiferous system - Leucosolenia sp. and Clathrina arnesenae. In both species, regeneration occurs due to the reconstruction of intact tissues adjacent to the wound. Epithelial morphogeneses (stretching, flattening and fusion of epithelial layers, exopinacoderm and choanoderm) play a central role in this process. Another important part of the regeneration is temporary transdifferentiation of the choanocytes into endopinocytes. At the same time, cell proliferation is not affected by the regenerative processes and does not contribute to the restoration of lost structures. Thus, the regeneration in Leucosolenia sp. and C. arnesenae is a rare example of "pure" morphallaxis, and the mechanisms used in regeneration are similar to those of Eumetazoa. Financial support by Russian Foundation of Basic Research №16-04-00084 and the Russian Science Foundation №17-14-01089 is gratefully acknowledged. How to cite: Lavrov AI, Bolshakov FV, Tokina DB and Erevkovsky AE. Regeneration in calcareous sponges (Calcarea, Porifera) of the White Sea [version 1; not peer reviewed]. F1000Research 2018, 7:1873 (slides) (https://doi.org/10.7490/f1000research.1116325.1)