The representation of the organs that form blood cells in the sea urchin Paracentrotus lividus and determination of the importance of sialic acids in blood cell differentiation with microscopic (light, fluorescent, TEM) and analytical (CapLC-ESI/MS-MS System) methods
Project no. 575 · Status: Kapanmış · 2014
Summary
Echinoderms, usually living in coastal waters, are directly exposed to pathogenic microorganisms. Because of that, they have active immune systems. These defense mechanisms are regulated by cellular and humoral responses. Humoral responses are carried out by a wide variety of secreted compounds that can be found in the celomic fluid and play important roles in immunity. Cell-based immunity is carried out by the coelomocytes, which present diverse functions including phagocytosis, encapsulation, clotting, cytotoxicity, wound healing and the production of antimicrobial agents. Despite their importance in immune system, the origin of coelomocytes is still controversial. The axial organ of Paracentrotus lividus is compose of the Peripheral sinus at dorsal, Haemal lacunae close to Peripheral sinus, Axial coelom at ventral, and numerous Canaliculi that is way down from haemal lacunae towards axial coelom. Polian vesicles are embedded in a mesenteric structure on the aristotle's lantern. They are in the form of grapes and consist of several small vesicles. According to the results of microscopic studies, we observed different types of Coelomocytes in Axial organ and Polian vesicles. On the other hand, the connection between the axial organ and the Polian vesicles by stone canal and ring canal, and the release of coelomocytes from both tissues may be evidence for their possible roles in the immune system. In this study, to determine the origin of coelomocytes, we described histological and cytological structure of axial organ and Polian vesicles in sea urchin, P. lividus. We showed first time the connection between Axial organ, Polian vesicles and coelomocytes. Our results provide important clues about the origin, maturation and storage of coelomocytes. In addition, for the first time, we described histological and cytological structure of Polian vesicles in sea urchin. Our results will be helpful to further studies about the origin of coelomocytes and immune regulatory mechanisms in sea urchin. Key words: Sea urchin Immune System, Axial organ, Polian Vesicles, Coelomocyte, Paracentrotus lividus.