Summary
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1.
During multiplication of irradiated cells, a segregation may take place between bleached cells, whose progeny is unable to green, and green ones. Some of the green cells give progenies exclusively made of green cells; the progeny of others is partly composed of bleached cells.
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2.
If one assumes that greening results from the activity of functional units endowed with genetic continuity (Plastidial Segregating Units=PSU), segregation of these units seems to occur according to a model involving random sorting out during the three first divisions. During the following divisions, functional units seem to multiply faster than those impaired by irradiation.
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3.
The greening rate of colonies issued from irradiated cells seems to be conditioned mostly by the number of functional PSU remaining in the mother cell of the colony.
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References
Diamond, J., Schiff, J.A.: Insensibility of photosynthetic competence to doses of ultraviolet light which block green colony formation in Euglena. Canad. J. Bot. 48, 1277–1283 (1973)
Ebringer, L.: Are plastids derivated from prokaryotic microorganisms? Action of antibiotics on chloroplasts of Euglena gracilis. J. gen. Microbiol. 71, 35–52 (1972)
Freyssinet, G., Heizmann, P., Verdier, G., Trabuchet, G., Nigon, V.: Influence des conditions nutritionnelles sur la réponse à l'éclairement chez les euglènes étiolées. Physiol. Vég. 10, 421–442 (1972)
Gibor, A., Granick, S.: The plastid system of Euglena gracilis. J. Protozool. 9, 327–334 (1962a)
Gibor, A., Granick, S.: Ultraviolet sensitive factors in the cytoplasm that affect the differentiation of Euglena plastids. J. Cell Biol. 15, 599–603 (1962b)
Gibor, A., Herron, H.A.: Chloroplast inheritance. In: The biology of Euglena, Vol. 2 (D.E. Buetow, ed.), pp. 335–349. New-York: Academic Press 1968
Goldstein, N.H., Schwartzbach, S.D., Schiff, J.A.: Conservation of plastid forming units (PFU) during bleaching in Euglena gracilis var. bacillaris. J. Protozool. 21, 443 (1974)
Grenson, M.: Physiology and cytology of chloroplast formation and “loss” in Euglena. Int. Rev. Cytol. 16, 37–59 (1964)
Hill, H.Z., Schiff, H.A., Epstein, H.T.: Studies of chloroplast development in Euglena. XIII: Variation of ultraviolet sensitivity with extent of chloroplast development. Biophys. J. 6, 125–133 (1966)
Innocent, J.P.: Les mutants blancs d'Euglena gracilis: production et propriétés génétiques. Thèse de spécialité Lyon (1974)
Latarjet, R., Morenne, P., Berger, R.: Un appareil simple pour le dosage des rayonnements ultraviolets émis par les lampes germicides. Ann. Inst. Pasteur 85, 174–185 (1953)
Lyman, H., Epstein, H.T., Schiff, J.A.: Studies of chloroplast development in Euglena. I: Inactivation of green colony formation by U.V. light. Biochim. Biophys. Acta (Amst.) 50, 301–309 (1961)
Manning, J.E., Richards, O.C.: Isolation and molecular weight of circular chloroplast DNA from Euglena gracilis. Biochim. biophys. Acta (Amst.) 259, 285–296 (1972)
Manning, J.E., Wolstenholme, D.R., Ryan, R.S., Hunter, J.A., Richards, O.C.: Circular chloroplast DNA from Euglena gracilis. Proc. nat. Acad. Sci. (Wash.) 68, 1169–1173 (1971)
Michaels, A., Gibor, A.: Ultrastructural changes in Euglena after ultraviolet irradiation. J. Cell Sci. 13, 799–809 (1973)
Mitchell, J.L.A.: Photoinduced division synchrony in permanently bleached Euglena gracilis. Planta (Berl.) 100, 244–257 (1971)
Pontier, J.: Théorie de la cible: un modèle markovien pour l'évolution génétique d'une mutation latente. Acta biotheor. (Leiden) 22, 120–141
Rawson, J.R.Y., Boerma, C.L.: Influence of growth conditions upon number of chloroplast DNA molecules in Euglena gracilis. Proc. nat. Acad. Sci. (Wash.) 73, 2401–2404 (1976)
Schiff, J.A.: Photocontrol of chloroplast and cytoplasm during chloroplast development in Euglena. In: Les cycles cellulaires et leur blocage chez plusieurs protistes, éditions du C.N.R.S., pp. 79–93 (1975)
Schiff, J.A., Lyman, H., Epstein, H.T.: Studies of chloroplast development in Euglena. III: experimental separation of chloroplast development and chloroplast replication. Biochim. biophys. Acta (Amst.) 51, 340–346 (1961)
Uzzo, A., Lyman, H.: The nature of the chloroplast genome of Euglena gracilis. In: Proc. of the 2nd Int. Congr. on Photosynth. Res. (G. Forti, ed.), 3, 2585–2601. The Hague: Dr W. Jung N.V. Publishers 1971
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Nicolas, P., Innocent, JP. & Nigon, V. Somatic segregation and rate of greening after ultraviolet irradiation of Euglena gracilis . Molec. gen. Genet. 155, 123–129 (1977). https://doi.org/10.1007/BF00393150
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DOI: https://doi.org/10.1007/BF00393150