ISSN:
1432-0878
Keywords:
Encapsulation
;
Polychaete worm (Nereis)
;
Invertebrate immunity
;
Coelomocytes
;
Freeze-fracture
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Foreign bodies implanted into the coelomic cavity of the polychaete annelid, Nereis diversicolor, are rapidly encapsulated by coelomocytes. This phenomenon was studied ultrastructurally with thin sections and freeze-fracture preparations. A lysis of cells on the surface of the implant occurs. The cells discharge organelles that coat the foreign surface. Numerous flattened granular coelomocytes envelop the implant, forming a multilayered capsule composed of several distinct regions. A degranulation occurs in the deep layers of coelomocytes and gives rise to a large amount of dense substance that runs into the intercellular spaces and flows onto the surface of the implant. In the intermediate layers, the cohesion between coelomocytes is ascribed to numerous desmosomes. Gap junctions are also present; the reactive cells contain large numbers of microfilaments and microtubules. A superficial layer (the “crown”) is characterised by rounded coelomocytes with filopodia.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00218214
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