Responses of Schistosoma mansoni Miracidia to Chemical Attractants

MacInnis, A. J.

doi:10.2307/3276148

Cited by 100 publications

(12 citation statements)

References 14 publications

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“…The responses of miracidia after contact with the snail host have been described in detail for miracidia of S. mansoni (MacInnis, 1965). The behavioral patterns "repeated investigation" and "attachment" seem to be the typical responses upon contact with the suitable host snails.…”

Section: Miracidial Behavior After Contact With the Hostmentioning

confidence: 99%

Echinostomes as Experimental Models for Biological Research

Fried¹,

Graczyk²

2000

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Section: Miracidial Behavior After Contact With the Hostmentioning

confidence: 99%

Echinostomes as Experimental Models for Biological Research

Fried¹,

Graczyk²

2000

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“…However, at 1–3 h post-hatch, miracidia use phototactic and geotactic cues to migrate to snail habitats, and do not respond to host chemosensory cues [7, 8]. After 1–3 h post-hatch, host attractant biomolecule(s) can be detected, reported to be non-specific small molecular weight biomolecules, and this was supported by experimental assays showing an increase in miracidia turn-back responses [9]. Further, macromolecular glycoconjugates referred to as miracidia-attracting glycoconjugates, have been implicated following an observed induction of changes to miracidial turn-back responses [10, 11].…”

Section: Introductionmentioning

confidence: 98%

GPCR and IR genes in Schistosoma mansoni miracidia

et al. 2016

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Background Schistosoma species are responsible for the disease schistosomiasis, a highly prevalent helminthic disease that requires a freshwater snail as intermediate host. The S. mansoni free-living miracidium must utilize olfaction to find a suitable snail host, and certain types of rhodopsin G protein-coupled receptors (GPCRs) and ionotropic receptors (IRs) have been identified as olfactory receptors in other animal phyla. The Schistosoma genome project, together with the recent availability of proteomic databases, allowed for studies to explore receptors within S. mansoni, some of which may contribute to host finding.ResultsWe have identified 17 rhodopsin-type GPCR sequences in S. mansoni belonging to four subclasses, including ligand-specific GPCRs (i.e. neuropeptide and opsin). RT-PCR demonstrated the expression of nine out of the 17 GPCRs in the free-living miracidia, each of which have been characterized for homology to S. haematobium. Among the nine GPCRs, two are predicted as Gq-opsins. We also describe the characterization of a Schistosoma-encoded IR based on similarity with other species IR and conservation of IR-like domains. Schistosoma mansoni IR is expressed in miracidia at 3 and 6 h post-hatch.ConclusionsThe identification of receptors in S. mansoni miracidia, presented here, contributes not only to further understanding of Schistosoma biology and signal transduction but also provides a basis for approaches that may modify parasite behaviour.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1837-2) contains supplementary material, which is available to authorized users.

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“…Until 1990, non-specific small molecular weight compounds from water, enriched with snail molecules (snail conditioned water, SCW), were considered as stimuli for miracidial host-finding behaviour (increase of rate of change of direction, RCD; turn-back responses; MacInnis 1965). Recent studies revealed that macromolecular glycoconjugates from SCW seem to be the only cues within SCW inducing such responses (miracidia-attracting glycoconjugates, MAGs; Kalbe et al 1997;Haberl et al 2000).…”

Section: Introductionmentioning

confidence: 99%

Snail odour-clouds: spreading and contribution to the transmission success of Trichobilharzia ocellata (Trematoda, Digenea) miracidia

et al. 2005

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Chemical communication among freshwater organisms is an adaptation to improve their coexistence. Here,we focus on the chemical cues secreted by the freshwater gastropod Lymnaea stagnalis, which are known to stimulate behavioural responses of Trichobilharzia ocellata (Plathelminthes, Digenea, Trematoda) miracidia. Such responses are commonly claimed to influence transmission positively, but in response to chemical cues miracidia randomly change their swimming direction. This kind of response does not necessarily increase transmission, because miracidia may be trapped at the periphery of very large snail odour-clouds, which may prevent them from approaching the snail. On the other hand, the odour clouds may be too small to improve host-localisation. To shed light on these scenarios, the spreading of molecules released around L. stagnalis (active space) was visualised by recording host-finding responses of T. ocellata miracidia when they approached snails. Behavioural responses of miracidia indicated the spreading of compounds forming an attractive active space only around the host-snail L. stagnalis, but not around sympatric non-host-snail species. The active space increased approximately linearly with the time the snail rested at the same spot and within 5 min it reached a volume of more than 30 times that of the snail. We also demonstrated in a large-scale experiment, that the active space of L. stagnalis significantly increases the transmission success of T. ocellata miracidia. Additionally, the microhabitat selection of T. ocellata miracidia was studied, demonstrating that peripheral locations near the water surface were preferred, which are also preferred sites of L. stagnalis. Improved chemoperception and microhabitat selection may have been a consequence of coevolution with snails and benefited miracidia, which became efficient transmissive stages.

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Responses of Schistosoma mansoni Miracidia to Chemical Attractants

Cited by 100 publications

References 14 publications

Echinostomes as Experimental Models for Biological Research

Echinostomes as Experimental Models for Biological Research

GPCR and IR genes in Schistosoma mansoni miracidia

Snail odour-clouds: spreading and contribution to the transmission success of Trichobilharzia ocellata (Trematoda, Digenea) miracidia

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