Tissue specific control of alpha-fetoprotein gene expression.

The expression of the alpha-fetoprotein (AFP) gene was studied in rat liver and kidney. A significant level of AFP mRNA was found in neonatal liver and kidney, but not in adult tissues. Unlike liver the re-expression of AFP mRNA was not seen upon chemically induced regeneration of the kidney. Treatment of neonatal rats with dexamethasone caused a decrease in liver AFP mRNA levels, but a similar decrease was not apparent in kidney. Northern analysis revealed AFP mRNA size to be identical in neonatal liver and kidney. The results suggest different gene regulatory mechanisms in liver and kidney for the AFP gene.