Figure 4.

Molecular analysis of albumin-cre mutant livers. (A) DNA blot analysis of two albumin-cre mutant livers. The genotype as determined by tail DNA analysis is indicated. Note the appearance of a new band (1-lox allele) in lane 2 and a shift in the ratio of the two bands toward the 1-lox allele in lane 1, indicating albumin-cre mediated recombination. (B) Analysis of VHL target gene expression by RNA blot. Lanes 1–5 represent total RNA samples from mutant livers; lanes 6 and 7 are controls. (C) HIF-2α expression in mutant livers. HIF-2α is detected in mutant livers and absent from wild-type control livers. The two nonspecific background bands were found in all mouse samples and are not present in the human sample. Whole-cell protein extracts from CoCl₂-treated HELA cells and an anemic mouse liver were used as positive controls. The mouse HIF-2α protein is slightly larger than the human homologue (37), hence the small difference in migration between the two species.