Pattern of ribonucleic acid synthesis during germination of Allomyces macrogynus mitospores

The relationship between ribonucleic acid (RNA) synthesis and germination of Allomyces macrogynus mitospores was investigated. It was determined that the synthesis of all classes of RNA was initiated during the first 10 min of germination, around the time of encystment. It is during this stage that the membrane of the nuclear cap structure begins to break down, dispersing the cell complement of ribosomes throughout the cytoplasm. After encystment, there was an increase in the rate of synthesis of the four stable RNA species (4S, 5S, 19S, and 27S) which leveled off as the germ tube emerged. Data suggested that messenger RNA was synthesized at an increasing rate during the course of germination. Studies of RNA precursor pool behavior and RNA synthesis in the presence and absence of actinomycin D indicated that no species of RNA, including messenger RNA, was synthesized in the presence of actinomycin D. Further, precursor pool measurement indicated that the apparent increase in the rate of RNA synthesis during germination was largely due to increased specific activity of the RNA precursor pool.