Abstract
Fern gametophytes were grown under blue light with and without the addition of 5-fluorouracil or 8-azaguanine, and under red light. Nucleic acids were extracted by either the detergent-chloroform or the detergent-diethylpyrocarbonate method and analyzed by polyacrylamide gel electrophoresis. No significant differences in the relative distribution of the stable RNA components accompanied the transition to biplanar growth. The RNA content per average cell decreased with growth and also varied between the cultural conditions, yet it was independent of the pattern of morphological development. The falling RNA content per average cell resulted from a progressive reduction of the RNA content of the apical cell, as determined histochemically. Since filamentous growth occurred by division of this apical cell, the rate of cell division was independent of the RNA content of the dividing cell.