Symmetric DNA Adenine Methylation Plays an Essential Role in Early-Diverging Fungi [ChIP-seq]
The discovery of N6-methyladenine (6mA), typically found in prokaryotic DNA, in eukaryotic genomes, has revolutionized epigenetics. Here, we show that symmetric 6mA is essential in the early diverging fungus Rhizopus microsporus, as the absence of the MT-A70 complex (MTA1c) responsible for this modification results in a lethal phenotype. 6mA is present in 70% of the genes, correlating with the presence of H3K4me3 and H2A.Z in open euchromatic regions. This modification is found predominantly in nucleosome linker regions, influencing the nucleosome positioning around the transcription start sites of highly expressed genes. Controlled downregulation of MTA1c results in a reduction of symmetric 6mA sites affecting nucleosome positioning and histone modifications, leading to altered gene expression, which is likely the cause of lethality. Our study highlights the indispensable role of the DNA 6mA in a multicellular organism and delineates the mechanisms through which this epigenetic mark regulates gene expression in a eukaryotic genome Overall design: ChIP experiments to determine H3K4me3, H3K9me3 and H2A.Z distribution in the R. microsporus genome as well as the binding profile of P1 (mCherry-tagged)