Number of replication origins active at each cell cycle

Range 30,000 - 50,000 replication origins/cell cycle
Organism Chinese hamster
Reference Méchali M. Eukaryotic DNA replication origins: many choices for appropriate answers. Nat Rev Mol Cell Biol. 2010 Oct11(10):728-38. doi: 10.1038/nrm2976. p.728 left column bottom paragraphPubMed ID20861881
Primary Source Huberman, J. A. & Riggs, A. D. Autoradiography of chromosomal DNA fibers from Chinese hamster cells. Proc. Natl Acad. Sci. 55, 599–606 (1966).PubMed ID5221245
Comments p.728 left column 2nd paragraph:"Pioneering work by Huberman and Riggs (primary source) showed that in mammals, 30,000–50,000 origins are active at each cell cycle. Not all origins are activated at the same time their activation follows the specific timing of DNA replication during the cell cycle (Fig. 1b). No consensus sequence has been identified to predict the localization of DNA replication origins in metazoans, and the degree of similarity between origin recognition in metazoans and the replicon model in E. coli (ref 2) (whereby sequence-specific proteins recognize a sequence-specific DNA element) is also questioned. Moreover, it is now recognized that potential replication origins are in excess and only a subset are activated at each cell cycle. This leads to the notion of flexible origins, which are used stochastically at each cell cycle or with an increased use in stress conditions or in specific cell cycles." Cells of Chinese hamster fibroblast strain B14FAF28
Entered by Uri M
ID 111771