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vasa (vas)-related genes are members of the DEAD-box protein family and are expressed in the germ cells of many Metazoa. We cloned vasa-related genes (PpVLG, CpVLG) and other DEAD-box family related genes (PpDRH1, PpDRH2, CpDRH, AtDRHr) from the colonial parasitic rhizocephalan barnacle Polyascus polygenea, the non-colonial Clistosaccus paguri (Crustacea:(More)
Commercial crab populations off the Kamchatka coasts are infested to a considerable degree by the rhizocephalan parasite Briarosaccus callosus: of 769 Lithodes aequispina males examined, 43 (5.7%) were parasitized. Infestations result in the feminization of the crabs, a significant decrease in the cheliped length, and a significant decrease in the carapace(More)
Topological patterns in the development and evolution of metazoa, from sponges to chordates, are considered by means of previously elaborated methodology, with the genus of the surface used as a topological invariant. By this means metazoan morphogenesis may be represented as topological modification(s) of the epithelial surfaces of an animal body. The(More)
Diversity of blastogenesis and embryogenesis in animals with different reproductive strategy and different variants of the isolation of germ lineage cells, defined in the literature as preformation, epigenesis, and somatic embryogenesis, is discussed. In the course of somatic embryogenesis (or, more precisely, blastogenesis), the oozooid that has developed(More)
An ultrastructural study of nuage-mitochondria complexes in spermatogonia of the sea urchin, Anthocidaris crassispina, was carried out. Release of mitochondrial contents into the cytoplasm was observed. The mitochondrial derivatives persisted as cristae-containing globules of friable material that subsequently contacted and integrated with nuage. The(More)
The colonial internae of two decapod parasites Peltogasterella gracilis and Sacculina polygenea (Crustacea: Cirripedia: Rhizocephala) were studied in vitro by histological, and histochemical methods. We found stem cells, characterized by basophilic cytoplasm, a large nucleus and nucleolus, and a high alkaline phosphatase activity. The cytochemical(More)
Biological systems are considered that are capable of dynamic self-organization, i.e., spontaneous emergence of spatio-temporal order with the formation of various spatio-temporal patterns. A cell is involved in the organization of ontogenesis of all stages. Embryonic cells exhibit coordinated social behavior and generate ordered morphological patterns(More)
The review presents a topological interpretation of some morphogenetic events through the use of well-known mathematical concepts and theorems. Spatial organization of the biological fields is analyzable in topological terms. Topological singularities inevitably emerging in biological morphogenesis are retained and transformed during pattern formation. It(More)
This paper presents a topological interpretation of some developmental events through the use of well-known concepts and theorems of combinatorial geometry. The organization of early embryo using a simulation of cleavage considering only blastomere contacts is examined. Each blastomere is modeled as a topological cell and whole embryo--as cell packing. The(More)
Published and original data indicating evolutionary conservation of the morphofunctional organization of reserve stem cells providing for asexual and sexual reproduction of invertebrates are reviewed. Stem cells were studied in representatives of five animal types: archeocytes in sponge Oscarella malakhovi (Porifera), large interstitial cells in colonial(More)