The distribution of F-actin during the development of Diphyllobothrium dendriticum (Cestoda)

Abstract

The distribution of actin filaments in all developmental stages of the tapeworm Diphyllobothrium dendriticum was studied. It is the first investigation of the placement of microfilaments during the development of a flatworm, and the results show that actin filaments, in all developmental stages, can be found in the subtegument and the flame cells. Muscle fibers possibly corresponding to the longitudinal, transversal, and dorsoventral muscles of the adult and plerocercoid were already detected in the procercoid. Concerning the adult worm, a new set of longitudinal fibers in the peripheral parts of the adult proglottid was found. The ducts of the protonephridial system and the vitellarias were seen to be surrounded by longitudinally oriented actin filaments, while the uterine ducts and the vagina were encircled by microfilaments. Prominent layers of circular muscle fibers surrounded the cirrus and the seminal vesicle, and radial fibers were also detected. Areas faintly stained with TRITC-phalloidin were found in the developing germ cells, the cells of the genital anlage, vitelline cells, the tegument, and the main nerve cords. None of these structures were autofluorescent, which is also true concerning the intensively labeled oncospheral hooks.

Visualization and 3D Reconstruction of Flame Cells of Taenia solium (Cestoda)

“…The expression of the protein in similar cells was observed in other cestodes such as D. dendriticum [6], in the monogenean G. rysavyi [7] and the trematode S. mansoni [9]. In the former, it was found as part of a ring situated in the middle portion of their ciliated cells while in the later, with 3D reconstructions, it was found to be concentrated in a hollow barrel.…”

“…In tapeworms, FC appear to be beating continuously, their cilia producing the impression of flickering flames inside the cell [4], and due to this behavior, FC have also received names like cap cells and bulb cells [5]. Knowledge of cytoskeletal proteins of FC have shown that polymerized actin was found by fluorescent phalloidin in FC of the cestode Diphyllobothrium dendriticum [6] and in the monogenean Gyrodactylus rysavyi [7] where it was associated to longitudinal fibers that are in close contact with the PS excretory system. Tubulin was demonstrated in FC cilia of the cestode Gymnorinchus [8] and in the trematode Schistosoma mansoni [9].…”

The neuro-muscular system in cercaria with different patterns of locomotion

“…The whole mounts were incubated with the primary antibody for 5 days at 7°C, then they were washed with PBS-T and incubated with the secondary antibody swine anti-rabbit FITC (DAKO) (1:50) or goat anti-mouse Alexa 546 or goat anti-mouse Alexa 488 (Molecular Probes, USA) (1:800) for 5 days at 7°C. In order to study the spatial relationship between the patterns of the 5-HT-IR or FMRF-IR nervous elements and the musculature, the immunocytochemical (ICC) staining was followed by staining the F-actin fibres with TRITCconjugated phalloidin (Sigma, USA) (1:200) for 30-60 min at 7°C according to Wahlberg (1998). Furthermore, in order to understand the whole picture of the NMS we stained the specimens with antibodies towards α-tubulin according to Cebrià (2008).…”

The spatial relationship between the musculature and the 5-HT and FMRFamide immunoreactivities in cercaria, metacercaria and adult Opisthorchis felineus (Digenea)

“…The whole mounts were incubated with the primary antibody during 5 days at 4°C, then they were washed with phosphate buffered saline-triton (PBS-T), and incubated with the secondary antibody swine anti-rabbit FITC (fluorescein isothiocyanate) (DAKO) 1:50 for a further 5 days at 4°C. In order to study the spatial relationship between nerves and musculature, the immunochemical staining was followed by staining the actin fibres with TRITC (rhodamine B isothiocyanate)-conjugated phalloidin (Sigma) (1:200) for 1 h at 4°C according to Wahlberg (1998). After a final wash in PBS-T, the specimens were mounted in 50% glycerol-PBS for examination with a Leica TCS 4D confocal scanning laser microscope coupled to a Leitz Aristoplan.…”