The development of daughter sporocysts inside the mother sporocyst ofSchistosoma mansoni with special reference to the ultrastructure of the body wall

Meuleman, Elisabeth A.; Holzmann, Paulina J.; Peet, Richard

doi:10.1007/bf00925512

Cited by 40 publications

(20 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A similar origin for the tegument has been proposed for the developing larvae of other species of digeneans (BILS & MARTIN, 1966;DIXON & MERCER, 1967;MEULEMAN & HOLZMANN, 1975;HOCKLEY, 1972;MEULEMAN et al, 1980;JOHNSTON, 1983;GOBEL & PAN, 1985;AL-SALMAN & JAMES, 1988). By contrast, JAMES (1973) stated that the tegument of several species of opercoelid cercariae was derived from cells lying beneath the outermost layer of cells of germinal balls.…”

Section: Discussionmentioning

confidence: 80%

Embryological development of the cercarial tegument of Paramphistomum epiclitum in the planorbid snail, Indoplanorbis exustus

Dunn¹,

Dang

Hanna

et al. 1992

J. Helminthol.

View full text Add to dashboard Cite

Cercariae develop from individual germinal cells occurring freely within the posterior body cavity of rediae. Individual germinal cells give rise to a germinal ball which becomes enveloped by increasing numbers of cytoplasmic extensions originating from specialized parenchyma-like cells, termed nurse cells. Up to eight cytoplasmic layers of nurse cells invest larger germinal balls. These layers may provide mechanical support for developing embryos and/or play a role in the provision of nutrients to them. The cercarial tegument develops from superficially located somatic cells in the germinal ball. Cytoplasmic extensions of presumptive tegumental cells fuse laterally to form a syncytial layer beneath the encapsulating nurse cell layers. As the cercarial tegument differentiates further, the cytoplasm of the nurse cell layers becomes vacuolated and ultimately these layers degenerate. The surface tegumental syncytia of intra-redial cercariae and newly released extra-redial cercariae are nucleated. Separate subtegumental perikarya develop with further differentiation of extra-redial cercariae.

show abstract

Section: Discussionmentioning

confidence: 80%

Embryological development of the cercarial tegument of Paramphistomum epiclitum in the planorbid snail, Indoplanorbis exustus

Dunn¹,

Dang

Hanna

et al. 1992

J. Helminthol.

View full text Add to dashboard Cite

show abstract

“…4,9,10). The tegument of the sporocyst undergoes advanced changes compared to the miracidium (Southgate 1970, Køje et al 1976, Meuleman et al 1980) and becomes an absorptive structure, substituting for the intestine and, on the other hand, protects the sporocyst against the host enzymes (Threadgold 1984, Bryant 1994. This explains the high intensity of metabolism of the sporocyst tegument.…”

Section: Discussionmentioning

confidence: 91%

Some specific and non-specific phosphatases of the sporocyst of Fasciola hepatica. II. Enzymes associated with the membrane transport

Humiczewska¹

2002

FOLIA PARASIT

View full text Add to dashboard Cite

Abstract. Using histochemical and cytophotometric methods, enzymes responsible for the membrane transport (alkaline phosphatase, adenosine triphosphatase, and 5-nucleotidase) in the developing sporocyst of Fasciola hepatica (L., 1758) were studied. The most active metabolism occurred in the germ balls of sporocysts on the 8th and 15th days of development, which is associated with intensive proliferation and subsequently differentiation of embryos within the germ balls.Sporocyst, the first parasitic developmental stage of the liver fluke, Fasciola hepatica (L., 1758) has a form of a baggy larva of very simplified structure compared to the free-living miracidium, from which it evolves in tissues of a snail (Humiczewska 1975, 1988, Czapski 1977. The sporocysts develop most frequently in the mantle wall, which is the site of entry of the miracidium, but they are being encountered also in the lung-sacs, gonads, and in the glands of alimentary tract of the snail. Almost all organs typical of the miracidium vanish in the sporocyst except for the germ balls embedded in the parenchyma and covered from the outside with the tegument.Due to such fundamental morphological changes, as well as the life style changes from free-living to parasitic, it is reasonable to expect also significant metabolic changes of the sporocyst. The knowledge on the physiological, metabolic, and behavioural adaptations of parasites has been still incomplete, so it was justified to undertake this type of studies. The present work is the second in a series devoted to this subject and it is aimed at determining the location and the activity of the enzymes associated with the membrane transport within the sporocyst during its development from juvenile to adult form. The present studies, showing the metabolic processes of the parasite can contribute to the explanation of its adaptation capabilities. MATERIALS AND METHODSThe sporocysts were acquired through infection of Galba truncatula (O.F. Mull.) snails with the miracidia reared in vitro (Humiczewska 1975). The snails from the laboratory cultures were exposed to 20 miracidia each. The detailed procedure of the culture and the way of exposure were described in the first part of the present series (Humiczewska 1996). Histochemical studies on the developing sporocysts were carried out on 3rd, 8th and 15th days after exposure. The sporocysts representing the respective developmental periods varied in size (0.2-0.8 mm), shape, and developmental advancement of the germ balls (Humiczewska 1975(Humiczewska , 1988(Humiczewska , 1996.The infected snails assigned to the histochemical studies, after shell removal, were frozen with dry ice and cut in a cryostat to 10 µm thick sections. The Gomori precipitation method (Pearse 1968) was used for detection of alkaline phosphatase (EC 3.1.3.1), while the Wechstein and Meisel method (Pearse 1968) was employed in search for adenosine triphosphatase (EC 3.6.1.3) and for 5-nucleotidase (EC 3.1.3.5). The control reactions were performed using substrate-lacking incubation ...

show abstract

“…A freshwater snail is infected with a short-lived and free-swimming miracidia. After invasion into the snail, the miracidia transforms into a mother sporocyst and undergo clonal expansion to produce daughter sporocysts [18]. The full maturation of the sporocyst occurs over 5 weeks and is marked by production of infectious cercariae.…”

Section: Introductionmentioning

confidence: 99%

LncRNAs in molluscan and mammalian stages of parasitic schistosomes are developmentally-regulated and coordinately expressed with protein-coding genes

2020

View full text Add to dashboard Cite

Despite the low level expression of some long noncoding RNAs (lncRNAs), the differential expression of specific lncRNAs plays important roles during the development of many organisms. Schistosomes, parasitic flatworms that are responsible for schistosomiasis, infects over 200 million people resulting in chronic disease and hundreds of thousands of deaths. Schistosomes have a complex life cycle that transitions between molluscan and mammalian hosts. In a molluscan snail host, the sporocyst stage develops over 5 weeks undergoing asexual reproduction to give rise to free-swimming and infectious cercariae that penetrate human skin and eventually mature into egg producing worms in mammals. The tight integration of the sporocyst to the snail host hepatopancreas hinders the-omics study in the molluscan stage, so the sporocyst transcriptome has only been examined for lncRNAs in immature in vitro samples. Here we analyzed the in vivo mature sporocyst transcriptome to identify 4,930 total lncRNAs between the molluscan and mammalian stages of the parasite. We further demonstrate that the lncRNAs are differentially expressed in a development-dependent manner. In addition, we constructed a co-expression correlation network between lncRNAs and protein-coding (PC) genes that was used to identify clusters of lncRNA transcripts with potential functional relevance. We also describe lncRNA-lncRNA and lncRNA-kinome correlations that identify lncRNAs with prospective roles in gene regulation. Finally, our results show clear differential expression patterns of lncRNAs in host-dependent development stages of S. mansoni and ascribe potential functional roles in development based on predicted intracellular interaction.

show abstract

The development of daughter sporocysts inside the mother sporocyst ofSchistosoma mansoni with special reference to the ultrastructure of the body wall

Cited by 40 publications

References 17 publications

Embryological development of the cercarial tegument of Paramphistomum epiclitum in the planorbid snail, Indoplanorbis exustus

Embryological development of the cercarial tegument of Paramphistomum epiclitum in the planorbid snail, Indoplanorbis exustus

Some specific and non-specific phosphatases of the sporocyst of Fasciola hepatica. II. Enzymes associated with the membrane transport

LncRNAs in molluscan and mammalian stages of parasitic schistosomes are developmentally-regulated and coordinately expressed with protein-coding genes

Contact Info

Product

Resources

About