Gene Dose Ratio of the BarH2 and BarH1 genes in D. melanogaster. DNA samples (0.5 ng/μl) were obtained from pooled thorax samples of males or females from wild type (Or-R) and mutant B1 strains. GDR values are relative to the number of RpS3 gene copies in each sample. The primer pairs used for each gene amplification are indicated below the bars. Error bars represent the SE from three replicates.