FIG. 8.

Histone acetylation and brahma recruitment by GFP-lac rep-ER fusion proteins. A03_1 cells were transfected with GFP-lac rep-ER, GFP-lac rep, or GFP-lac rep-VP16 and treated with 10⁻⁹ M estradiol for various time points prior to fixation and staining with antibodies against the acetylated forms of histone H3 and H4 or against brahma. (A) For histone acetylation (left set of images), each cell's lac operator array was scored as having staining at a lower level than (hypoacetylated), comparable to (neutral), or higher than (hyperacetylated) that for the rest of the chromatin in the nucleus. For brahma recruitment (right set of panels), each cell's lac operator array was scored as having staining comparable to that for the rest of the nucleus (not recruited), slightly brighter staining relative to the rest of the nucleus (borderline), or brighter staining than the rest of the nucleus (recruited). (B) For each time point, cells were scored as in panel A for histone H3 acetylation (left) and histone H4 acetylation (middle) and brahma recruitment (right).