Cyclobutane pyrimidine dimers (CPDs) are formed in DNA following exposure to ultraviolet (UV) light and are mutagenic unless repaired by nucleotide excision repair (NER). It is known that CPD repair rates vary in different genome regions owing to transcription-coupled NER and differences in chromatin accessibility
however, the impact of regional chromatin organization on CPD formation remains unclear. Furthermore, nucleosomes are known to modulate UV damage and repair activity, but how these damage and repair patterns are affected by the overarching chromatin domains in which these nucleosomes are located is not understood. Here, we generated a new CPD damage map in