THE COMPARATIVE CHARACTERISTIC OF MORPHOLOGY AND PROLIFERATIVE ACTIVITY OF COELOMIC FLUID AND COELOMIC EPITHELIUM CELLS IN STARFISH ASTERIAS AMURENSIS AND STARFISH A. RUBENS.

Identification and characterization of cells responsible for the restoration of tissues in adult organisms is one of the main problems in regenerative biology. In this study, the comparative histological analysis of cellular suspensions in coelomic fluid (CF) and coelomic epithelium (CE) of two close species of Asteroidea has been done. Particular attention was paid to characteristics of small epithelial cells (SECs, diameter 4 mm) with high nuclear-cytoplasmic ratio more 0.9 and without visible signs of differentiation. Cells of this type constitute a significant proportion in CE in Asterias rubens, show proliferative activity and are probably the progenitor cells for the coelomocytes. Small cells with parameters identical to those of A. rubens SECs have been found both in CF and CE of A. amurensis. We have found subpopulation of weakly attached CE cells highly enriched with SECs-1. These cells were able to migrate from CE. Analysis of adhesion ability of CF and CE cells has revelaled the same patterns for these two closely releated starfish. Two-week primary cultures have demonstrated the speciality of A. amurensis CE cells consisting in the formation of «crystals¼, the potential centers of spiculogenesis that have not been revealed in A. rubens. Both small cells and larger cells with nuclear-cytoplasmic ration lower than 0.7 demonstrated proliferative activity in vivo and in vitro. Moreover, more high mitotic activity of coelomocytes has been found in A. amurensis. The hypotheses of coelomocytes origin are discussed.

[The characteristic of the coelomic fluid and coelomic epithelium cell populations of starfish Asterias rubens L., capable to attach and spread on various substrates].

Cultivation is one of the methods modeling processes occurring in vivo. The success of cultivation, in particular, is defined by a substratum choice. We studied the ability of coelomocytes and coelomic epithelial cells to attach and spread to fibronectin, laminin, polylysine, and glass. Qualitative composition of heterogeneous populations of coelomocytes and epithelial cells was determined after staining the cells with rhodamine-phalloidin and DAPI, and changes in the composition of populations evaluated in response to injury. Seven relative classes of coelomocytes has been identified, three of which has been shown to participate in the formation of clot during primary repair of wounds. There was a change in the proportion of these cells, attached to specific ligands in response to the injury. In coelomic epithelium 8 relative classes of cells has been identified, two of which are likely to be candidates for the role of progenitor cells for coelomocytes--coelomocyte-like and small epithelial cells with high nuclear-cytoplasmic ratio. The enrichment with the small cells in population of attached coelomic epithelium cells has been revealed when seeding on laminin. Continued viability of epithelial cells has been shown when cultured on laminin during 2 months.

[Cells of coelomic liquid and cells of different tissues of sea star Asterias rubens L. isolated from intact and post-traumatic animals: behaviour and proliferation under cultivation in vitro].

Proposed sources of coelomocytes in Asteroidea after traumatic injures are coelomic epithelium, axial organ or Tidemann's bodies. To study the involvement of cell division in the process, proliferation of cells from different tissues of starfish Asterias rubens L. has been studied after bromdeoxyuridine incorporation in vivo. To study the differentiation of coelomocytes in vitro a method for isolation and cultivation of different tissue cells has been worked out and cell behaviour and proliferation in culture has been analyzed. The reliable BrdU incorporation has been found in coelomic epithelium cells in vivo. Coelomocytes and coelomic epithelium cells behaviour in culture dependent on the post-trauma period after which the cells were loaded into the culture whereas no difference was revealed for axial organ and Tidemann's bodies cells. Two-month cultivation of coelomic epithelium cells resulted in formation of colony-like accumulations of the cells with high nuclear-cytoplasm ratio which of colony-like accumulation of the cells with high nuclear-cytoplasm ratio which incorporated BrdU. Thus, coelomic epithelium cells seem to be more promising object for the study of A. rubens cell differentiation in vitro.