Transcriptional control of the murine albumin/alpha-fetoprotein locus during development.

The ontogeny of expression of the alpha-fetoprotein (AFP) and albumin genes was examined in livers from late prenatal to 1-month-postpartum C3H/He mice. A parallel accumulation of both AFP and albumin mRNAs before birth, followed by a selective nonreciprocal decrease in AFP mRNA after birth, was observed. The decrease in AFP mRNA was the result of a decrease in transcription of the AFP gene, as measured by an in vitro nuclear transcription assay. We suggest a model for hepatic expression of the AFP and albumin gene cluster in which transcription of the two genes is activated simultaneously during differentiation and each gene is thereafter modulated independently in committed cells.