Figure 4.

HP1a preferentially inhibits NUEGs on chromosome 4 and stimulates expression of UEGs in pericentromeric regions. The mean expression ratio (log₂ scale) of NUEG (gray boxes) and UEG (black boxes) genes in Pof, HP1a, HP1a Pof, Setdb1 and Su(var)3-9 mutants in, (A) chromosome 4 (NUEGs: n = 37, UEGs: n = 32 for Pof mutant and NUEGs: n = 45, UEGs: n = 32 for the other mutants), (B) in pericentromeric regions (NUEGs: n = 27, UEGs: n = 52 for Pof mutant and NUEGs: n = 30, UEGs: n = 52 for the other mutants) and (C) in cytological region 2L:31 (NUEGs: n = 19, UEGs: n = 52 for Pof mutant and NUEGs: n = 20, UEGs: n = 52 for the other mutants). Squares indicate the mean value and whiskers indicate the 95% confidence interval. Dashed lines indicate no change in expression ratio. (D–G) Average meta-gene profiles of HP1a binding in NUEG (gray lines) and UEG (black lines) genes on chromosome 4 (D), pericentromeric regions (E), cytological region 2L:31 (F) and chromosome 3R as an HP1a-unbound control region (G). The profiles were compiled based on all active genes in the four regions in a wild-type background and each profile was generated on eight enrichment values on the x-axis. The first point of the curve is an average of the intergenic region upstream of the designated promoter of each gene. The promoter was defined as the 500-bp region upstream of the TSS. The gene body was divided into five bins, and the average enrichment in introns is the last point on the curve. The y-axis shows enrichment on a log₂ scale.