Defining DNA repair pathways that protect against 5-methylcytosine deamination.

We have used genetic approaches to investigate DNA repair pathways that protect against 5-methylcytosine deamination. New genetic models were established to allow for inactivation of DNA repair genes, including Mbd4, Tdg and Msh6, either alone, or in combination. Genome sequencing was applied to assess patterns of DNA damage evident in each model. DNA was extracted from clonal cell populations, including myeloid cell lines, bone marrow progenitors and colorectal organoids. We also profiled thymomas that developed spontaneously in Msh6 knockout mice. Wherever possible, matched germline material was included in our analysis to help improve the detection of somatic variants.