Figure 4.

(A) Steady-state mRNA levels of pancreatic islet enriched genes of wild-type (WT), Pdx-1^+/−, Hnf-3β^+/−, Hnf-1α^+/−, Pdx-1^+/−/Hnf-3β^+/−, and Pdx-1^+/−/Hnf-1α^+/− mutant mice. The housekeeping gene hypoxanthine phosphoribosyltransferase (Hprt) was amplified to show that each sample contained similar amounts of mRNA. A lack of any amplification signal in reactions without reverse transcriptase (−RT) shows that genomic DNA did not contaminate the samples. Transcript levels were measured in three animals for each genotype by RT-PCR using [α-³²P]dCTP. PCR products were separated by PAGE, and bands were visualized by autoradiography. (B) Quantitative measurements of gene expression were obtained by densitometry, and the mean of measurements are shown ± SD. The level of significance of the different comparisons (single- vs. double-heterozygous mutant) is shown on the right.