Fig. 5. A critical role for K-Ras in liver development. (A) Expression of the early hepatic marker gene, α-fetoprotein (AFP). A 10 µg aliquot of total RNA extracted from wild-type, K-Ras^+/– or K-Ras^–/– fetal liver at E14.5 was loaded in each lane (rRNA; loading control). mRNA expression of AFP was determined by northern blotting using a DIG-labeled probe. (B) mRNA expression of differentiation markers in K-Ras^–/– fetal hepatocytes. Fetal hepatocytes at E14.5 derived from wild-type, K-Ras^+/– or K-Ras^–/– liver were cultured for 6 days with Dex or Dex/OSM. Total RNA (10 µg) extracted from each culture was analyzed by northern blotting to investigate expression of TAT, G6Pase or GAPDH (internal control). (C) Localization of E-cadherin in K-Ras^–/– fetal hepatocytes. Fetal hepatocytes derived from wild-type, K-Ras^–/– or H-Ras^–/–N-Ras^–/– embryonic liver were cultured for 6 days with Dex or OSM/Dex and were fixed and stained with anti-E-cadherin antibody. Scale bar: 10 µm.