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La continuité génétique des chloroplastes chez les euglènes I. Mécanisme de l'apparition des lignées blanches dans les cultures traitées par la streptomycine

par Grenson, Marcelle ;Messin, S
Référence Biochimica et biophysica acta, 27, C, page (145-155)
Publication Publié, 1958

Article révisé par les pairs

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Résumé :

When a culture of Euglena is treated with streptomycin (Sm) during 2 to 10% of the generation time, and then transferred to normal medium, the formation of the chloroplasts is stopped for several generations and then resumes. During the period of transitory inhibition of the multiplication of the chloroplasts, the chloroplasts are equally distributed between the daugther cells, resulting in a mixture of cells with one chloroplast per cell and other cells without chloroplasts (the number of these increasing with time). As soon as the multiplication of the chloroplasts resumes, the normal number of 8 chloroplasts per cell is rapidly recovered. But nevertheless there remains a number of definitely white cells (without chloroplasts) which gives rise to white clones. The results of a study of the percentage of white to green clones isolated by plating once per generation during the first phase of the phenomenon agree with the idea that all that Sm does is to selectively decrease the growth rate of the chloroplasts which, when lost, cannot be formed de novo. © 1958.