Table 2:

Common genotoxins, their primary effects, and associated DNA lesions.

Genotoxin	Primary Effect	DNA Lesion	Citation
Hydroxyurea	Nucleotide depletion via ribonucleotide reductase (RNR) inhibition	Stalled replication forks, fork collapse	[187]
Cisplatin	DNA interstrand crosslinks	Fork collapse, double strand breaks (DSBs)	[188]
Camptothecin	Topoisomerase I inhibition	Replication stress, fork collapse, double strand breaks (DSBs)	[189]
Mitomycin C	DNA interstrand crosslinks	Fork collapse, double strand breaks (DSBs)	[190]
Phleomycin	IR mimetic	Clustered DNA damage resulting in DSBs	[191]
4-Nitroquinoline oxide	Bulky base adducts	Bulky lesions primarily repaired by nucleotide excision repair (NER)	[192]
Methyl methanesulfonate	DNA base alkylation	ssDNA gaps and replication stress (S phase), DSBs breaks at high concentrations	[193]
Ionizing radiation	Clustered DNA damage from ionization cascade	DSBs with complex ends requiring nucleolytic processing	[194]
Break induction by programmable nuclease	Targeted phosphodiester backbone cleavage by nuclease	DSBs	[181]
Normal DNA Replication	DNA replication stress (mild)	Fork stalling, limited local fork collapse	[36, 195]