Transcription factors are required for the maintenance of NDRs. Nucleosomal and NDR patterns generated by tiling microarrays of control cells (972 h-) and of atf1 Δ and pcr1 Δ mutants are represented by black, red and blue lines, respectively. Sites of Atf1 and Pcr1 binding mapped by ChIP/Chip  are indicated by red and blue arrowheads. Black arrows indicate NDRs that disappear in the absence of Atf1 or Pcr1 and white arrows point to NDRs not bound by Atf1 and Pcr1 that remain invariable in the three strains. Strand-specific transcription profiles for the three strains are shown in green. Alternative transcription start sites of the SPAC22F8.05 (top diagram) and SPAC922.04 (bottom diagram) genes associated with the closing of NDRs dependent on Atf1 and Pcr1, are indicated by brackets.