+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Functional ultrastructure and cytochemistry of vitellogenesis and mature vitellocytes of the digenean Cainocreadium labracis (Dujardin, 1845), parasite of Dicentrarchus labrax (L., 1758)

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          Vitellogenesis and vitellocytes of Cainocreadium labracis were studied by transmission electron microscopy (TEM) and TEM cytochemistry. Four developmental stages were distinguished during vitellogenesis: (I) stem cell of high nucleo-cytoplasmic ratio; (II) early differentiation with chief activity focused on the beginning of protein synthesis and shell globule formation; (III) advanced differentiation with rapid intensification of protein synthesis, progressive fusion of single shell globules into large globule clusters, and formation of unsaturated lipid droplets surrounded by β-glycogen particles; and (IV) mature vitellocyte. Early vitellogenesis with vitellocyte maturation consists of: (1) increase in cell volume; (2) increased development of large, parallel cisternae of GER with production of proteinaceous granules; (3) development of small Golgi complexes that package granules; and (4) within vacuoles, progressive enlargement of proteinaceous granules into shell globule clusters formed during vitellogenesis. Three types of inclusions accumulate in large amounts in mature vitelline cells: (1) shell globule clusters, important component in the formation of egg shell; (2) numerous unsaturated lipid droplets. Though fewer, there are also diphasic droplets consisting of saturated and unsaturated lipids in the same droplet, and (3) a relatively small amount of β-glycogen particles, usually surround a few groups of lipid droplets. The β-glycogen and lipid droplets are nutritive reserves for embryogenesis. General pattern and functional ultrastructure of vitellogenesis greatly resemble those observed in some lower cestodes, such as bothriocephalideans and diphyllobothrideans. Variations and differences in the amount of lipids and of glycogen during vitellogenesis in lower cestodes and other trematodes are compared and discussed.

          Related collections

          Most cited references 53

          • Record: found
          • Abstract: not found
          • Article: not found

          Mise en évidence des polysaccharides sur coupes fines en microscopie électronique

            • Record: found
            • Abstract: found
            • Article: not found

            Ovoviviparity in platyhelminth life-cycles.

             Colin Tinsley (1983)
            The encapsulated embryos of platyhelminths may be retained and complete their development in utero in a range of circumstances. However, hatching within the parent (the criterion of ovoviviparity) is relatively rare and larvae generally emerge only after deposition. Viviparity is characterized by the nutritional dependency of the unencapsulated larva upon the parent, but in several cases larvae retained within a shell also receive parental nutrients during intra-uterine development. Uptake of exogenous nutrients via shell pores occurs in Schistosoma mansoni but the eggs, which gain all the advantages of intra-uterine retention, are supported by host nutrients. Intra-uterine larval development avoids the hazards of development in the external environment and eliminates the time delay between oviposition and infection. Deposition of immediately infective offspring may be concentrated in time and space to exploit periods of host vulnerability. The control and precision of transmission is illustrated by examples in which the opportunity for invasion is restricted because of either host behaviour or environmental instability. This strategy has been an important factor in the evolution of polystomatid monogeneans, and its effectiveness is demonstrated by comparison of the life-cycles of Polystoma integerrimum and Pseudodiplorchis americanus. Ovoviviparity also increases reproductive potential in some polystomatids by extending the period of multiplication and by increasing established populations through internal re-infection. In Eupolystoma alluaudi, the capacity for ovoviviparity is programmed into larval development and this regulates population growth within individual hosts.
              • Record: found
              • Abstract: found
              • Article: not found

              Vitellocytes and vitellogenesis in cestodes in relation to embryonic development, egg production and life cycle.

              Vitellocytes have two important functions in cestode embryogenesis: (1) formation of hard egg-shell (e.g. Pseudophyllidea) or a delicate capsule (e.g. Cyclophyllidea), and (2) supplying nutritive reserves for the developing embryos. During evolution any of these two functions can be reduced or intensified in different taxa depending on the type of their embryonic development, degree of ovoviviparity and life cycles. Within the Cestoda, there are three monozoic taxa with only one set of genital organs: Amphilinidea, Gyrocotylidea and Caryophyllidea. In these monozoic taxa and some polyzoic groups with well developed vitellaria (e.g. Pseudophyllidea, Trypanorhyncha) a single oocyte [=germocyte] and a large number of vitellocytes (up to 30) are enclosed within a thick, hardened egg-shell, forming a type of eggs typical for the basic pattern of Neodermata. Only one type of egg-shell enclosures, the so-called 'heterogeneous shell-globule vesicle' is common for the above mentioned cestode taxa. Each membrane-bounded vesicle of mature vitellocytes contains numerous electron-dense shell globules embedded in a translucent matrix. In free-living Neoophora and Monogenea there are two types of vesicles with dense granules; the second is considered to be proteinaceous reserve material. Within the Cestoda, the numbers of vitellocytes per germocyte are reduced in those taxa forming eggs of the 'Cyclophyllidean-type' (e.g. Cyclophyllidea, Tetraphyllidea, Pseudophyllidea). This is particularly evident in Cyclophyllidea; for example, in vitellocytes of Hymenolepis diminuta (Hymenolepididae) there are numerous vitelline granules of homogeneously electron-dense material; in Catenotaenia pusilla (Catenotaeniidae) there are three large, homogenous vitelline vesicles, while in Inermicapsifer madagascariensis (Anoplocephalidae) there is only one large vitelline vesicle, containing homogeneously electron-dense material, which occupies most of the vitelline cell volume. In this respect the Tetraphyllidea and Proteocephalidea, in forming eggs that lack a hard egg-shell, hold an intermediate position. A comparison of interrelationships which exist among types of vitellocytes, vitellogenesis, types of embryonic development, ovoviviparity and life cycles indicates parallelisms and analogies in adaptation to the parasitic way of life in different groups of cestodes. Knowledge on cestode vitellogenesis may also have an important applied aspect. Vitellocytes, due to their high metabolic rate, represent a very sensitive target for analysing effect of anthelminthic drugs upon the egg formation (ovicidal effects); rapid degeneration of vitellocytes is usually accompanied by a cessation of egg production.

                Author and article information

                +34 93 4024500 , z.swider@twarda.pan.pl
                Parasitol Res
                Parasitol. Res
                Parasitology Research
                Springer Berlin Heidelberg (Berlin/Heidelberg )
                26 December 2018
                26 December 2018
                : 118
                : 2
                : 493-504
                [1 ]ISNI 0000 0001 1958 0162, GRID grid.413454.3, Witold Stefański Institute of Parasitology, , Polish Academy of Sciences, ; 51/55 Twarda Street, 00-818 Warsaw, Poland
                [2 ]ISNI 0000 0001 2323 5644, GRID grid.412124.0, Laboratoire de Biodiversité et Ecosystèmes Aquatiques, Département des Sciences de la Vie, , Faculté des Sciences de Sfax, ; BP 1171, 3000 Sfax, Tunisia
                [3 ]Department of Biological Sciences, University of New York at Albany, Albany, NY 12222 USA
                [4 ]ISNI 0000 0004 1937 0247, GRID grid.5841.8, Secció de Parasitologia, Departament de Biologia, Sanitat i Medi Ambient, Facultat de Farmàcia i Ciències de l’Alimentació, , Universitat de Barcelona, ; Av. Joan XXIII, sn, 08028 Barcelona, Spain
                [5 ]ISNI 0000 0004 1937 0247, GRID grid.5841.8, Institut de Recerca de la Biodiversitat (IRBio), , Universitat de Barcelona, ; Av. Diagonal, 645, 08028 Barcelona, Spain
                © Springer-Verlag GmbH Germany, part of Springer Nature 2018

                Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

                Helminthology - Original Paper
                Custom metadata
                © Springer-Verlag GmbH Germany, part of Springer Nature 2019


                Comment on this article