Design inteligente na replicação do DNA ‘just-in-time’

sábado, novembro 08, 2008

Just-in-time DNA replication [PDF Grátis]
Physics 1, 32 (2008) DOI: 10.1103/Physics.1.32

Suckjoon Jun and Nick Rhind 1FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138

2Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605

Published October 27, 2008

Genome replication originates at random places along the DNA strand, yet replication of the genetic material finishes within a defined time. A model based on phase-transition kinetics in condensed-matter systems explains how this just-in-time replication can happen.

A Viewpoint on:

How Xenopus laevis embryos replicate reliably: Investigating the random-completion problem

Scott Cheng-Hsin Yang (楊正炘) and John Bechhoefer

Phys. Rev. E 78, 041917 (2008) – Published October 27, 2008

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About the Author

Suckjoon Jun has always been obsessed with the remark by François Jacob, one of the founders of molecular biology, “The dream of every cell is to become two cells.” During his graduate studies in theoretical biophysics and soft-condensed-matter physics at Simon Fraser University, Canada, his main interest was physics underlying DNA replication. He then moved on to study DNA segregation at the FOM–Institute AMOLF in Amsterdam for his first postdoctoral assignment, where he showed theoretically that replicating chromosomes in E. coli and other bacteria can segregate, driven by their conformational entropy. He then had a brief affair with evolution and moved to Paris to work in Miro Radman’s laboratory at L’Hospital Necker until he arrived at Harvard in 2007. His physical biology laboratory is trying to understand the extent to which basic physical principles governing the fundamental biological processes involving chromosomes during the cell cycle.

Nick Rhind studied math and biology as an undergraduate at Brown University and found the biology a lot easier. He went on to do his graduate work at U.C. Berkeley, working on the genetics of sex-determination in the round worm C. elegans. For his postdoctoral assignment, he moved to the Scripps Research Institute to study cell-cycle regulation in fission yeast with Paul Russell. There, he became interested in how and why cells regulate the cell cycle in response to DNA damage. He has continued with that line of research in his own laboratory at the University of Massachusetts Medical School, focusing recently on the regulation of DNA replication by DNA damage. This work has led to an interest in more general questions about the regulation of DNA replication and to a return to his mathematical roots.