ИСТИНА

Porifera is the most primitive extant Metazoa group. Their anatomical structure and cell lines are very flexible as demostrated by the ability of sponge cells to reaggregate after tissue dissociation. Reaggregation leads to the formation of multicellular aggregates and in certain cases results in regeneration of functional sponges. In this work we used three species from the White sea: Halichondria panicea, Haliclona aquaeductus and Halisarca dujardini. Cell suspensions were obtained by the mechanical dissociation of tissues in FSW. Reaggregation process starts immediately after tissue dissociation. Cells of examined species remain stationary but actively form pseudopodia. In the case of contact between pseudopodia of different cells the pseudopodia begin to contract and cells merge forming multicellular aggregates. Cell reaggregation of H.panicea and H.aquaeductus displays similar pattern. Multicellular aggregates appear after 24 hours in the cell suspensions of these species. On the 3rd day the cell sorting occurs in the aggregates leading to the formation of the cell debris capsule around aggregates. In the next two days multicellular aggregates disengage from capsules, obtaining regular spherical shape and attaining stage of early primmorphs. It was the last stage in the reaggregation of H.aquaeductus cells. Early primmorphs of H.panicea transform into primmorphs on 7th-10th day by forming pinacoderm layer on their surface. This stage was the last in H.panicea cell reaggregation. H.dujardini cells reaggregation occurs much quicker. In this species multicellular aggregates appear in the cell suspensions within several hours. After 24 hours multicellular aggregates transform into primmorphs. By this moment the regeneration of functional sponges begins. It completes on 10th-12th day when oscula of small sponges open. This work will provide the basis for more detailed studies of the sponge cell reaggregation. It is necessary to examine the role and behavior of different cell types, reconstitution of ECM and anatomical structures during this process. How to cite: Lavrov AI and Kosevich IA. Cells reaggregation process of three sponge species from the White Sea [version 1; not peer reviewed]. F1000Research 2017, 6:1045 (poster) (doi: 10.7490/f1000research.1114345.1)