Fig. 1.

Generation of Idol-deficient ES cells. (A) Schematic diagram of the Idol gene, which spans ∼19 kb and contains 7 exons. The gene-trapping cassette (containing an en2 splice acceptor site (En2SA) and a β-galactosidase-neo fusion [βgeo]) was inserted into intron 1, and a downstream loxP site was inserted into intron 2. pA, polyadenylation signal; Beta-gal, β-galactosidase; Neo, neomycin phosphotransferase II. (B) β-Galactosidase was expressed in ES cell lines carrying a ßgeo gene trap cassette (WT2, Idol−/−1, and Idol−/−2), as judged by staining with X-Gal. WT1, the parental ES cell line, is shown for comparison. WT2 is targeted for the Tle3 gene. LPD, LPDS-containing medium. (C) Idol gene expression was determined in ES cells (n = 5) cultured in 10% FBS or LPDS-containing medium for 8 h and then treated with the LXR agonist GW (1 μM) for 16 h. The WT1 FBS point was assigned a value of 1, and data are plotted as fold induction over this level. Shown are means ± SD.