Identification of Chemicals triggering Cercarial Penetration Responses of Schistosoma mansoni

MacInnis, A. J.

doi:10.1038/2241221a0

Cited by 40 publications

(21 citation statements)

References 4 publications

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“…The results of recent behavioral studies of motile trematode larvae (Chemin, 1970;MacInnis, 1969;Wilson and Denison, 1970) suggest the presence of specialized sensory receptors in these organisms. Examination of a number of species at the electron microscope level has confirmed that modified nerve endings exist, and these are generally assumed to be sensory.…”

Section: Discussionmentioning

confidence: 95%

The Fine Structure of Ciliated Nerve Endings in the Cercaria of Schistosoma mansoni

Nuttman¹

1971

The Journal of Parasitology

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Section: Discussionmentioning

confidence: 95%

The Fine Structure of Ciliated Nerve Endings in the Cercaria of Schistosoma mansoni

Nuttman¹

1971

The Journal of Parasitology

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“…Since MT schistosomula are not exposed to skin lipids that are known to play a role in transformation [18], [19] and induce the release of contents from the acetabular glands [20], we had anticipated observing differences related to the presence of lipids in the ST. However, we could not identify transcripts related to the binding (fatty-acid binding proteins) or to the transport of fatty acids and therefore conclude that the effect elicited by the presence of skin lipids is independent from transcriptional regulation at that time and is more likely related to machinery that the parasite may already have in place prior to its encounter with host skin.…”

Section: Discussionmentioning

confidence: 99%

“…Various effectors are known to elicit the artificial transformation of cercariae into schistosomula, for example, cell growth media at 37°C [15], [16] or just low osmolarity phosphate buffer saline solution [17] seem to be enough to trigger the cercariae to schistosomula transformation. The presence of certain skin lipids, yet is not essential [17], also plays a role in the process of cercariae transformation and penetration [18], [19] probably by triggering the release of acetabular glands contents [20]. The most popular method for obtaining artificially transformed schistosomula uses a mechanical transformation (MT) protocol that includes some sort of shear force (centrifugation [21]–[23], passages through an emulsifying needle [24], or shaking [15]) applied to freshly shed cercariae followed by separation of cercariae heads from tails (usually by centrifugation in a density gradient) and posterior incubation of the cercariae heads/schistosomula in culture media at 37°C.…”

Section: Introductionmentioning

confidence: 99%

Comparative Study of Transcriptome Profiles of Mechanical- and Skin-Transformed Schistosoma mansoni Schistosomula

2013

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Schistosome infection begins with the penetration of cercariae through healthy unbroken host skin. This process leads to the transformation of the free-living larvae into obligate parasites called schistosomula. This irreversible transformation, which occurs in as little as two hours, involves casting the cercaria tail and complete remodelling of the surface membrane. At this stage, parasites are vulnerable to host immune attack and oxidative stress. Consequently, the mechanisms by which the parasite recognises and swiftly adapts to the human host are still the subject of many studies, especially in the context of development of intervention strategies against schistosomiasis infection. Because obtaining enough material from in vivo infections is not always feasible for such studies, the transformation process is often mimicked in the laboratory by application of shear pressure to a cercarial sample resulting in mechanically transformed (MT) schistosomula. These parasites share remarkable morphological and biochemical similarity to the naturally transformed counterparts and have been considered a good proxy for parasites undergoing natural infection. Relying on this equivalency, MT schistosomula have been used almost exclusively in high-throughput studies of gene expression, identification of drug targets and identification of effective drugs against schistosomes. However, the transcriptional equivalency between skin-transformed (ST) and MT schistosomula has never been proven. In our approach to compare these two types of schistosomula preparations and to explore differences in gene expression triggered by the presence of a skin barrier, we performed RNA-seq transcriptome profiling of ST and MT schistosomula at 24 hours post transformation. We report that these two very distinct schistosomula preparations differ only in the expression of 38 genes (out of ∼11,000), providing convincing evidence to resolve the skin vs. mechanical long-lasting controversy.

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“…These results indicate that it should be possible to formulate slowor no-release molluscicides coupled with controlled-release attractants. The attractants might be effective not only for snails but also for the larval stages of schistosomes, which likewise respond to amino acids (6,7).…”

mentioning

confidence: 99%

Schistosoma mansoni : Identification of Chemicals That Attract or Trap Its Snail Vector, Biomphalaria glabrata

Uhazy

Tanaka

MacInnis

1978

Science

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A new bioassay for chemical attractants of aquatic snails demonstrated that Biomphalaria glabrata could be attracted to or trapped in the vicinity of homogenates of lettuce. Fractionation of homogenates revealed the amino acids glutamate and proline and the primary attractants. Attraction was specific for the L form of glutamate. Proline appeared to stimulate reproductive activity. Glutathione, gamma-aminobutyric acid, and a number of other compounds had no effect. Extracts of lyophilized snail tissue also attracted other snails and may thus contain pheromones. These results permit formulation and testing of controlled-release attractants designed to overcome the repellant effects of slow-release molluscicides, as well as the design of stimulants to be used with no-release poisons.

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Identification of Chemicals triggering Cercarial Penetration Responses of Schistosoma mansoni

Cited by 40 publications

References 4 publications

The Fine Structure of Ciliated Nerve Endings in the Cercaria of Schistosoma mansoni

The Fine Structure of Ciliated Nerve Endings in the Cercaria of Schistosoma mansoni

Comparative Study of Transcriptome Profiles of Mechanical- and Skin-Transformed Schistosoma mansoni Schistosomula

Schistosoma mansoni : Identification of Chemicals That Attract or Trap Its Snail Vector, Biomphalaria glabrata

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