Ribosomal RNA in Frog Eggs Is Elevated by DNA Amplification

Time course of rDNA amplification in the Xenopus laevis oocyte. The amount of rDNA per cell is plotted against time. Note that the ordinate is a logarithmic scale. The sharp drop in rDNA at fertilization is thought to be due to dilution of the amplified rDNA copies by cell division, rather than to their destruction. (From A. P. 

Gene reiteration and gene amplification, Cell Biol. vol. 3, Gene Expression The Production of RNAs, L. Goldstein and D. M. Prescott (eds.), Copyright 1980 Academic Press, New York.) 

5S rRNA Synthesis in Frogs Requires a Regulatory Protein 

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