Figure 5.

Lid is a trimethyl H3K4 demethylase. (A–F) Flp/Gal4 was used to clonally express Lid (A–D) or Lid-JmjC* (E,F) in fat body cells to examine di- and trimethylated H3K4 levels (red). (A,C,E) Clones expressing Lid or Lid-JmjC* (full-length Lid protein containing two point mutations in the demethylase domain) are marked by coexpression of GFP, and these clones are outlined in the other panels. (G) Western blots from third instar larval wing discs from control (−) or apterous-Gal4 (+) and UAS-dMyc (lanes 1,2), one copy of UAS-Lid (lanes 3,4), two copies of UAS-Lid (lanes 5,6), or UAS-Lid-JmjC* (lanes 7,8). Westerns were probed with anti-Lid, anti-dMyc, anti-dimethyl H3K4, anti-trimethyl H3K4, or a total histone H3 control. Two wing discs were used per lane for all Westerns except 3MeK4, in which four were used. (H) Western analysis of wild-type (left) and lid¹⁰⁴²⁴ homozygous mutant (right) wing discs using anti-Lid, anti-monomethyl H3K4, anti-dimethyl H3K4, anti-trimethyl H3K4, or total histone H3.