engleski

Bioimaging of elements by NanoSIMS in different body parts of the acanthocephalan Dentitruncus truttae

The nanoscale secondary ion mass spectrometry (NanoSIMS), as a type of imaging mass spectrometry, represents a technique for elemental imaging that has not been widely applied in parasitology. Acanthocephalans are intestinal parasites of Mandibulata and Gnathostomata, and are recognised as bioindicators of metal exposure due to their effective metal accumulation. It was reported that acanthocephalans accumulate metals, especially toxic ones, at much higher concentrations than other indicator organisms, like fish, bivalves or crustaceans. Till now, there are no data on metal localisation in different body parts of acanthocephalans, even though these data may help us in understanding their successful metal uptake and storage. In the present study, the NanoSIMS was applied for localization of 11 elements, N, Fe, S, P, O, C, Na, Ca, Cu, Tl and Pb in three body parts of an acanthocephalan: trunk spines, inner part of the proboscis receptacle and the outer layer of the tegument. The chemical composition of the acanthocephalan body indicated complex structures that differed in the localization of the studied elements. In trunk spines, the highest element accumulation was found in the middle part, especially of S and Na, which were highly concentrated in the central ring, while Ca and C were mostly found in the whole spine area. The lower content of S, Ca and P in the proximal spine region might provide spine flexibility. In the proboscis receptacle the most dominant element was Ca, mostly located in the cytoplasmic inner lining and proboscis retractor muscles. The same pattern was found for Na, Fe, Cu, S, C and P, but in much lower concentrations. Considering outer layers of the acanthocephalan body, S and Na were mostly localised in contractile filaments of the muscle and intracellular matrix, while Ca was mostly found in the central cytoplasmic core of longitudinal muscles and neck retractor. Toxic metals were distributed along investigated structures without clear patterns and in very small quantities. The highest density in all studied structures was confirmed for Na, Ca, S, C, N, O, as important and constitutive elements in living cells, and among metals Fe was predominant in all analysed structures.

bioindicators ; metals ; thorny-headed worms

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