Ekaterina V Raikova

Learn More
Polypodium hydriforme is the only coelenterate adapted to intracellular parasitism in oocytes of acipenserid and polyodontid fishes. It occurs in both the Old and the New worlds, being parasitic in 12 species of Acipenseridae and in 1 species of Polyodontidae. Its earliest parasitic stages are binucleate cells that occur in previtellogenic oocytes. All(More)
  • E V Raikova
  • Journal of embryology and experimental morphology
  • 1976
Evolution of the nucleoli has been followed during oogenesis in the Acipenserid fishes, Acipenser ruthenus (the sterlet) and A. guidenstadti (the sturgeon) using light and electron microscopes. In the ovaries of adults, the oogonial nuclei usually have a single nucleolus with an adjacent mass of paranucleolar fibrillar material. The cytoplasm of the oogonia(More)
Polypodium hydriforme, the only species in Polypodiozoa, which is currently considered a class of Cnidaria, and likely a sister group to Medusozoa (together with Myxozoa), is a cnidarian adapted to intracellular parasitism inside sturgeon oocytes. Free-living P. hydriforme lives on river bottoms; it walks on supporting tentacles and uses sensory tentacles(More)
In situ hybridization has been performed in sections through ovaries ofAcipenser ruthenus andAcipenser güldenstädti in order to detect the rDNA sequences. Hybridization resulted in specific labelling of the “caps” of extrachromosomal DNA present in pachytene oocyte nuclei and of the chromatin granules distributed beneath the nuclear envelope in early(More)
Correction to Evans, N.M., Lindner, A., Raikova, E.V., Collins, A.G. and Cartwright, P. Phylogenetic placement of the enigmatic parasite, Polypodium hydriforme, within the phylum Cnidaria. BMC Evol Biol, 2008, 8:139. Correction Following the publication of this study [1] it was brought to our attention that the partial 28S rDNA sequence for Polypodium(More)
Structure of nematocysts from Polypodium hydriforme was studied by scanning and transmission electron microscopy. Two nematocyst types were observed: holotrichous isorhizas with minute spines, and true atrichous isorhizas. Among holotrichous isorhizas four morphological categories were distinguished based on differences in morphology of their discharged(More)
No significant differences in macro- and micromorphology were found between the parasitic stolon and free-living polyps of Polypodium sp. obtained from infected eggs of the North American acipenseriform fish Polyodon spathula and corresponding developmental stages of Polypodium hydriforme Ussov, parasitic in the Volga sterlet (Acipenser ruthenus).(More)
Musculature of the free-living stages of Polypodium hydriforme has been studied using phalloidin fluorescence method and confocal microscopy. P. hydriforme is a unique cnidarian possessing only smooth muscle cells situated within the mesoglea, not epithelial muscle cells, like the rest of cnidarians. Phalloidin fluorescence on whole mount preparations(More)