CPM Seminar

How frog embryos replicate their DNA quickly and reliably

John Bechhoefer

Department of Physics
Simon Fraser University

The genomes of higher organisms, such as frogs and people, contain several billion base pairs of DNA. In newly fertilized frog embryos, DNA replication is extremely rapid, about 20 min., and the entire cell cycle lasts only 25 min., meaning that mitosis (cell division) takes place in about 5 min. If for some reason replication has not finished at the end of 25 min., a “mitotic catastrophe” results. Despite a lack of ways to delay cell division if problems arise, such catastrophes are rare, occurring only about 1 in 250 times. How is such reliability possible despite a large amount of stochasticity in the replication process? I present a modelling approach with roots in condensed-matter treatments of the kinetics of phase transitions that suggests an answer to the above problem.