Article révisé par les pairs
Résumé : Autoradiographic experiments were undertaken to follow the metabolic abnormalities, due to hybridization, in the synthesis of nucleic acids and proteins. For the different precursors used ( 3H-thymidine, 3H-uridine, 3H-leucine, 14C-leucine, 14C-phenylalanine), the lethal hybrid P ♀ × A ♂ presents a pattern of incorporation intermediary between the parental types P ♀ × P ♂ and A ♀ × A ♂. In the extreme cases, the nuclei of the hybrids are labelled in an anarchic way by 3H-thymidine. An elimination of chromatin in the cytoplasm could explain these observations. The DNA of these nuclei accumulates in an abnormal manner in the blocked embryos and is less stable than the DNA of the control embryos. An accumulation of labeled RNA is observed in the nuclei of the hybrids at a stage (blastula) when a migration of nuclear RNA towards the cytoplasm is observed in the controls. Only, fertilized eggs (10 % in the case of the hybrids) are labelled in their proteins by the radioactive amino acids. There is slight inhibition of the incorporation in the hybrids P ♀ × A ♂ compared to the controls A ♀ × A ♂. © 1963.