Abstract
Messenger RNA was isolated, by means of its attachment to poly(A), from calf liver and the livers of mice, rats, and chickens. When injected into the uterine lumen of immature or spayed mice, both mouse albumin and the albumins characteristic of the species donating the mRNA were synthesized. Studies with inhibitors disclosed that puromycin blocked the synthesis of both albumin species, while dactinomycin affected only mouse albumin synthesis. It appears, therefore, that in the experimental situation used, the function of exogenous liver mRNA is 2-fold: (i) it programs the synthesis of alien albumin in uterine epithelial cells, and (ii) it stimulates the synthesis of mRNA in epithelial cells. The mRNA thus produced primes the synthesis of mouse albumin.