A Light-Inducible Strain for Genome-Wide Histone Turnover Profiling in Neurospora crassa

Histones are not statically embedded, but are constantly exchanged outside of DNA replication. This study reports the characterization and validation of a histone turnover reporter strain of Neurospora crassa, and the method employed. This strain utilizes FLAG-tagged histone H3 under the control of a light-inducible promoter. This study also preliminarily explores histone turnover defects at constitutive heterochromatin with the loss of the heterochromatin proteins DIM-2, HDA-1, DIM-5, and HPO. Overall design: ChIP-seq: We analyzed incorporated FLAG-tagged histone H3 in Neurospora crassa strains in wild-type, ?dim-2, ?hda-1, ?dim-5, and ?hpo backgrounds by chromatin immunoprecipitation. Strains were grown, crosslinked, lysed, modified nucleosomes were immunopurified, and associated DNA was sequenced.