imagine that you performed a forward genetic screen looking for drosophila mutants with phenotypes resembling mutants in genes encoding polycomb group proteins. you found a mutant, where repression of genes x is not maintained properly. by genetic mapping you identified five candidate genes which may be disrupted in your mutant. which candidate is most likely to contain the mutation? just a reminder; histone h3 lysine 9 methylation is a repressive modification, while histone h3 lysine 4 methylation and histone h3 acetylation are activating modifications.