Figure 8.

Structure and expression of the human IRGM gene. (a) (left panels) RT-PCR analysis of expression of IRGM in HeLa and GS293 cells. The b and c splice variants were amplified simultaneously by the same primer pair (IRGMs1-rGMS). A different downstream primer (IRGMs1-r1) internal to all the 3' splice forms was used to show differences in the overall expression level of IRGM in the two cell lines. No RT' indicates that no reverse transcriptase is included in cDNA preparation. The band immediately below the IRGMc band in GS293 cell material, indicated with an asterisk, is a nonspecific band amplified only in this cell line. The band was sequenced and is unrelated to IRGM. (right panel) Analysis of IRGM expression in human brain, liver and testis by RT-PCR. GAPDH was used as a control. (b) Five splice forms of the IRGM gene have been identified, as indicated: IRGM(a)-IRGM(e). The promoter and 5'-untranslated regions of the gene are associated with an ERV9 retroviral LTR. Scale-bar is given in base pairs.