Synthesis of vitellogenin in cultures of male and female frog liver regulated by estradiol treatment in vitro.

Using the frog Xenopus laevis, we show that the addition of physiological concentrations of estradiol to cultures of liver from untreated males rapidly induces the synthesis of large amounts of vitellogenin. Sustained synthesis of vitellogenin requires continuous exposure to estradiol. A nonestrogenic steroid, dexamethasone, does not induce vitellogenin synthesis but does induce increased synthesis of a different protein in liver cultures.