Figure 2.

RT–PCR characterization of gene expression in insulinomas and islet precursor cell (noninsulinoma) tumors from βGK–Tag mice. The RT–PCR amplification pattern of the indicated gene products are shown for eight different tumors, four of which were classified as insulinomas (lanes 1–4) and four as noninsulinomas (lanes 5–8) based on insulin immunostaining (Fig. 1). The insulinomas generally contained insulin (insulin II-top band, insulin I-bottom band), Pdx1, Pax4, Pax6, Nkx6.1, tyrosine hydroxylase (Th), and Glut-2 mRNAs, which were are not present in noninsulinoma tumors. Nkx2.2, Beta2/NeuroD, Isl1, simian virus 40 Tag, Sur1, GK, Hnf3β, and Hnf6 mRNAs were present in both tumor types.