Figure 2.

Induced ZAC expression in INS-R9-2 cells in reference to Lot1 expression endogenously and in normal rat islets. (A) Endogenous Lot1 in INS-R9-2 cells compared to ZAC expression induced by Dox. For a competitive RT-PCR evaluation, products of RNA samples from INS-R9-2 cells, using primers that amplify both Lot1 and ZAC and produce same length of PCR products (512 bp, in lane 1, 3, 5, 7), were digested by NdeI which cuts ZAC but not Lot1. PCR products of ZAC were cut into two fragments with 395 bp and 117 bp, those lower bands in lane 2, 4, 6, 8. (B) An approximate comparison of physiological level of Lot1 expression in the normal rat islet vs. ZAC that induced by Dox in INS-R9-2 cells. We compared, by competitive RT-PCR, ZAC vs. Lot1 level in an equal (by 18S) mixture of RNA from rat islets and INS-R9-2 cells stimulated by the indicated Dox concentrations. The two genes were distinguished by NdeI digestion. The lowest band in each lane is primer dimers. Ladder: 1 Kb Plus.