Spin transport in a DNA molecule modified by cytosine methylation

[Display omitted] •Spin transport in a methylated DNA molecule.•A change in the magnetoresistance by methylation of cytosine.•Landauer formula with the first principles approximation. Spin transport in a methylated DNA molecule sandwiched between ferromagnetic electrodes was examined based on the Landauer formula with the first-principles approximation. Although methylation increased the conductance of the DNA molecule, the raised width was very small to be discriminated using an analytical method. Contrastingly, cytosine methylation affected spin polarization, resulting in more than 10% change in the ratio of magnetoresistance. The change in magnetoresistance was enhanced with a certain degree of cytosine methylation, whereas segregated cytosine methylation was unable to induce a detectable change in the magnetoresistance. These results suggest the possibility of elucidating the relationship between cytosine methylation and epigenetics by assessing magnetoresistance in a DNA molecule in the future.