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ELECTRON MICROSCOPIC STUDIES ON THE OOGENESIS OF DRAGONFLY AND CRICKET WITH SPECIAL REFERENCE TO THE PANOISTIC OVARIES
Author(s) -
MATSUZAKI MORIO
Publication year - 1971
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1971.00379.x
Subject(s) - vitellogenesis , biology , golgi apparatus , anatomy , ultrastructure , cytoplasm , yolk , oocyte , microbiology and biotechnology , endoplasmic reticulum , membrane , oogenesis , biophysics , biochemistry , ecology , embryo
The successive ultrastructural changes during oogenesis in Sympetrum frequens (Odonata, Libellulidae) and Gryllus yemma (Orthoptera, Gryllidae) were studied. The structures of the terminal filament and boundary between the terminal filament and the germarium differed from each other in these 2 species; in Sympetrum the boundary between the terminal filament and the germarium was a special acellular transverse septum, whereas that in Gryllus was composed of several flattened cells which seemed to be similar to the prefollicular cells in the germarium. During the previtellogenesis, the nucleolar extrusions and emissions of the outer nuclear envelope were observed frequently in young oocytes. In Sympetrum , electron dense masses were observed in the oocyte cytoplasm, which seemed to be “yolk nuclei” or “Balbiani bodies” and were composed of aggregated small particles (about 200 A in diameter). They were gradually dispersed in the cytoplasm until the onset of vitellogenesis. In both Sympetrum and Gryllus , yolk precursors seemed to be incorporated into oocytes by micropinocytosis as observed in various animals. The egg membranes, viz. , the vitelline membrane and the chorion, seemed to be formed by products from follicle cells which developed rough‐surfaced endoplasmic reticulum and Golgi bodies. Thus, both of these egg membranes were assumed to be the secondary egg membranes.