Organized Filaments in the adhesive system of Macrostomum tuba Graff, 1882 ( Platyhelminthes, Macrostomida)
Braz. j. morphol. sci
;
23(3/4): 471-477, July-Dec. 2006. ilus
Artigo
em Inglês
| LILACS
| ID: lil-644246
ABSTRACT
The adhesive organs or duo-gland adhesive organs of platyhelminths are formed by a specialized epithelialcell and extensions of two gland cells. These organs are used for temporary fixation of the organism tosurfaces in aquatic habitats. The mechanisms involved in adhesion to and release from a given surfacedepend on secretions produced by the glands; less is known about the involvement of cytoplasmic filamentsin the anchoring cell itself. In this study, we examined the structure of the adhesive organs present in thetail plate of Macrostomum tuba Graff, 1882 (Platyhelminthes, Macrostomida), a freshwater, free-livingflatworm. Scanning and transmission electron microscopy allowed elucidation of the three-dimensionalorganization of the adhesive system, especially of the microvilli that formed the outer collar (or papilla),which was endowed with a fibrous core. Electrical stimulation caused the flatworms to extend their papillaeabove the ciliated surface. The use of tannin- and diamine-containing fixatives showed that the filamentousarray contained tonofilaments and actin filaments. Tonofilaments concentrate in the axis of each microvillus;actin filaments, about 7-8 nm thick, spread out towards the periphery. Scanning images demonstrated thefinger-like shape of the papillae, about 7-8 ìm high, with a terminal opening. Microvilli followed a straightcourse along the surface.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Platelmintos
/
Citoesqueleto de Actina
/
Actinas
Limite:
Animais
Idioma:
Inglês
Revista:
Braz. j. morphol. sci
Assunto da revista:
Anatomia
Ano de publicação:
2006
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
State University of Londrina/BR
/
University of São Paulo/BR
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