RNA Biosynthesis during Development of Chick Embryo

Abstract

Summary

The incorporation of 5-[³H]-uridine into the single RNA species of chick embryo has been studied between the third and twelfth days of incubation.

Ribosomal RNA precursor, Q₁-RNA, shows an almost constant rate of synthesis during the stages of development studied. r-RNA shows a decreased rate of incorporation of the label from the third to the sixth days, and a large peak at the eighth day of incubation.

DNA-like RNA species show a large peak of the incorporation rate at the seventh day of incubation (TD-RNA) and at the eighth day (Q₂-RNA). Another separate peak is shown by Q₂-RNA at the fourth to fifth days of incubation, while a shoulder is found at the same period in the pattern of TD-RNA.