Abstract: | A segment of chick elastin cDNA cloned in the plasmid pBR322 was sequenced by the method of Maxam and Gilbert ((1977) Proc. Natl. Acad. Sci. U. S. A. 74, 560-564) and the 192-base pair insert was found to be derived from the nontranslated region of the 3' end of the mRNA. The nick-translated cDNA was used to identify and to estimate the relative amounts of elastin mRNA in the developing chick embryo aorta by blot hybridization. A single species of 3.5 kilobases hybridized to the cDNA probe and this species increased greatly between day 7 and day 14 of embryonic development. This increase was paralleled by an increase in translatable aortic elastin mRNA and by the in vivo rate of elastin synthesis, demonstrating that the change in synthesis during development is largely controlled by the elastin mRNA content of the aorta. |