Average size of eukaryotic replicon is
Replicon size in eukaryotes measured by DNA fiber autoradiography and molecular combing reveals average distances between active origins. Yeast replicons average 40 kb, mammals show variable lengths depending on cell type and chromatin context, commonly 40-100 kb, occasionally up to 300 kb in late-replicating heterochromatin. Small replicons ensure complete duplication within 6-8 hour S phase with fork rates of 1-2 kb per minute. Origin density is regulated by checkpoint kinases ATR and Chk1, dormant origin reserve activated during replication stress. Thus experimental estimates converge on 40
Ref: Lodish et al., Molecular Cell Biology, 9th ed., Chapter 5: Average Size of Eukaryotic Replicon is 40-100 kb
