[RNA synthesis gradients in the nucleus-free fragments of Acetabularia mediterranea under conditions of local illumination]. / Gradienty sinteza RNK u bez'iadernykh fragmentov Acetabularia meditarranea v usloviiakh lokal'nogo osveshcheniia.

The intensity of RNA synthesis was studied in different regions of anuclear fragments of the Acetabularia mediterranea stem under their local illumination. The local illumination was shown to activate RNA synthesis and formation of distal-medial gradients of this synthesis in the illuminated regions of the fragments to a much greater extent than in their darkened regions. The formation of the gradient in the illuminated region took place even if the growth in this region was insignificant and was not accompanied by the cap formation. The results obtained suggests the absence of obligatory correspondence between the ability of morphogenesis and the gradient of RNA synthesis.

[Species specificity of morphogenetic factors of Acetabularia, localized in the cytoplasmic zone adjacent to the cell membrane]. / Vidospetsifichnost' morfogeneticheskikh faktorov Acetabularia, lokalizovannykh v prilegaiushchei k kletochnoi membrane zone tsitoplazmy

The species specificity of the factors controlling the cap development was established in the experiments with the transplantation of both the intact and centrifuged in the basal direction apical regions of Acetabularia meditteranea on nuclear basal regions of A. crenulata. These factors are found at the stage of 72 hrs of regeneration primarily in the cytoplasmic zone adjacent to the cell membrane which is not displaced during centrifugation. Using direct measurements and radiochemical method, we have shown that the accumulation of proteins proceeded in this zone due, mainly, to their transition from the cytoplasmic zone displaced during centrifugation.