par Ficq, Adrienne ;Urbani, E.
Référence Experimental cell research, 55, 2, page (243-247)
Publication Publié, 1969-05
Article révisé par les pairs
Résumé : In a brief description of the oogenesis of Dytiscus marginalis, attention is focused on the role and the significance of the Giardina body and the nurse cells, in this organism. A staining technique, with 3H-actinomycin followed by autoradiography, very sensitive for detecting acid-labile DNA has confirmed, with more details, the observations made after Feulgen staining: 1. 1. During the early stages, the Giardina body and the nuclei of the nurse and the follicle cells, bind 3H-actinomycin intensely. 2. 2. At more advanced stages, the nuclei of the nurse and of the follicle cells remain heavily labelled by 3H-actinomycin. Although these structures are the only ones to be Feulgen positive at that stage, after staining with 3H-actinomycin, the germinal vesicle of the oocyte is also labelled, and more weakly, the ooplasma. 3. 3. Feulgen positive granules are visible in the cytoplasm, surrounding the nuclear membrane. They are radioactive after staining with 3H-actinomycin and electron microscopy suggests a passage of nuclear material through the nuclear membrane. These results are discussed in the light of our present knowledge on the role of extra chromosomal DNA and of cytoplasmic DNA. © 1969.