Non-FRET-based fusion protein reporter molecules are provided that can be used to monitor histone modifications in living cells. Transgenic animals, particularly non-human mammals, whose genomes comprise an expression cassette encoding a non-FRET-based fusion protein reporter, are also provided. Methods of using the fusion reporter molecules for diagnosing histone-modification-associated disorders and to identify candidate pharmaceutical agents that effect histone modification in cells and tissues are also provided.