Figure 2

PCR amplification products ( copia LTR-CAT primers shown in Figure 1) of DNA prepared from intact nuclei (chromatin structure maintained) vs. DNA purified using standard procedures (chromatin structure not maintained-see Methods) digested (+) or not digested (-) with Apa I restriction enzyme. (a) The results indicate that the Apa I restriction site is accessible for digestion in nuclei preps (chromatin structure preserved) from wild-type larvae homozygous for the copia LTR-CAT construct but is not accessible for digestion in nuclei preps from larvae hemizygous for the construct in the wild-type genetic background. (b) The resistance of hemizygous copies of the copia LTR-CAT construct is lost in larvae homozygous for the mof¹ (loss-of-function) allele. All experiments were conducted with the 9-3 transformant strain. [wild type (mof +) = DNA from larvae carrying the wild-type allele at the mof locus; mutant (mof -) = DNA from larvae carrying the mof¹allele at the mof locus; homo = DNA isolated from larvae homozygous for the copia LTR-CAT construct; hemi = DNA isolated from larvae hemizygous for the copia LTR-CAT construct].