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Differentiation of totipotent germinal cells in larvae of bird schistosomes
Peštová, Jitka ; Horák, Petr (advisor) ; Chanová, Marta (referee)
This thesis aims to explore the larval development of a bird fluke Trichobilharzia regenti in its intermediate hosts, as well as the processes of differentiation of its embryonal cells and the differentiation between sporocystogenesis and cercariogenesis in sporocysts, with the ultimate goal to find out whether it is possible to find multiple generations of daughter sporocysts throughout the development of avian schistosomes in the intermediate hosts, just like in the case of human schistosomes of genus Schistosoma. Five developmental stages of daughter sporocysts, and ten developmental stages of cercariae have been defined. The first developmental stage in both larvae is the germinal cell. It divides and gives rise to a cell agregate. Afterwards an envelope (primitive epithelium) is formed around the embryo and subsequently, the embryo elongates. At this stage, the development of the two larvae undergoes different pathways. We can distinguish daughter sporocyst from cercaria in the phase, when the tegument is completed. The daughter sporocyst acquires characteristic vermiform appearance, and its body cavity contains plenty of germinal cells. For cercariae with an developed tegument, presence of the penetration glands is characteristic. Key words: Trichobilharzia regenti, germinal cells, mother...
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Differentiation of totipotent germinal cells in larvae of bird schistosomes
Peštová, Jitka ; Horák, Petr (advisor) ; Chanová, Marta (referee)
This thesis aims to explore the larval development of a bird fluke Trichobilharzia regenti in its intermediate hosts, as well as the processes of differentiation of its embryonal cells and the differentiation between sporocystogenesis and cercariogenesis in sporocysts, with the ultimate goal to find out whether it is possible to find multiple generations of daughter sporocysts throughout the development of avian schistosomes in the intermediate hosts, just like in the case of human schistosomes of genus Schistosoma. Five developmental stages of daughter sporocysts, and ten developmental stages of cercariae have been defined. The first developmental stage in both larvae is the germinal cell. It divides and gives rise to a cell agregate. Afterwards an envelope (primitive epithelium) is formed around the embryo and subsequently, the embryo elongates. At this stage, the development of the two larvae undergoes different pathways. We can distinguish daughter sporocyst from cercaria in the phase, when the tegument is completed. The daughter sporocyst acquires characteristic vermiform appearance, and its body cavity contains plenty of germinal cells. For cercariae with an developed tegument, presence of the penetration glands is characteristic. Key words: Trichobilharzia regenti, germinal cells, mother...
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Leishmania tropica in Mediterranean
Peštová, Jitka ; Votýpka, Jan (advisor) ; Sádlová, Jovana (referee)
In recent years new foci of Leishmania tropica appeared in the Mediterranean states of Northern Africa. While L. tropica was isolated from humans, dogs and sand fly species Phlebotomus sergenti in Morocco and from humans and gerbils (Gerbilus pyramidum floweri) in Egypt; in Tunisia, Algeria and Lybia the parasite was isolated from humans only. In the last three mentioned states, only L. tropica referred as Leishmania killicki is present. In most of the L. tropica foci in the Mediterranean countries of Northern Africa transmission mode was not determined. It is unknown whether the cycle of L. tropica is anthroponotic or zoonotic and what is reservoir and vector. In Morocco and Egypt, the most probable vector is P. sergenti only, while in Tunisia, Algeria and Lybia the vectors could be also P. (Paraphlebotomus) riouxi, P. (Paraphlebotomus) chabaudi, P. (Paraphlebotomus) alexandri or P. (Larroussius) perniciosus. Considering the rural distribution and sporadic occurence of L. killicki cases, the parasite is presumed to have a zoonotic cycle and its reservoir host could possibly be Ctenodactylus gundi, which is relatively abundant in L. kilicki foci.
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