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Influence d'irradiations UV localisées sur l'incorporation de l'adénine-8-14C, de l'uridine-3H et de la dl-méthionine-35S dans l'algue Acetabularia mediterranea

1961; Elsevier BV; Volume: 24; Issue: 1 Linguagem: Inglês

10.1016/0014-4827(61)90247-6

1090-2422

Maria Olszewska, F. De Vitry, Jean Brachet,

Marine Biology and Environmental Chemistry

The effects of localized UV radiation (tip or rhizoid) on cap formation and incorporation of labeled precursors (adenine-8-14C, uridine-3H and dl-methionine-35S) into RNA and proteins have been followed in Acetabularia. It has been found that the three precursors studied are incorporated first in the nucleus and that they are then distributed according to a decreasing apico-basal gradient in normal algae. After UV irradiation of the tip, cap production and incorporation of the precursors in the apical region are markedly decreased. Irradiation of the rhizoid has less effect on cap formation and markedly reduces the incorporation, but without modifying the apico-basal gradient. It is concluded that the nucleus controls the synthesis of RNA and sulfur-containing proteins, which accumulate in the apical part of the alga where they play an important role in morphogenesis.