How Xenopus laevis replicates DNA reliably even though its origins of replication are located and initiated stochastically.
نویسندگان
چکیده
DNA replication in Xenopus laevis is extremely reliable, failing to complete before cell division no more than once in 10 000 times; yet replication origin sites are located and initiated stochastically. Using a model based on 1D theories of nucleation and growth and using concepts from extreme-value statistics, we derive the distribution of replication times given a particular initiation function. We show that the experimentally observed initiation strategy for Xenopus laevis meets the reliability constraint and is close to the one that requires the fewest resources of a cell.
منابع مشابه
How Xenopus laevis embryos replicate reliably: investigating the random-completion problem.
DNA synthesis in Xenopus frog embryos initiates stochastically in time at many sites (origins) along the chromosome. Stochastic initiation implies fluctuations in the time to complete and may lead to cell death if replication takes longer than the cell cycle time ( approximately 25 min) . Surprisingly, although the typical replication time is about 20 min , in vivo experiments show that replica...
متن کاملPersistence Length of Chromatin Determines Origin Spacing in Xenopus Early-Embryo DNA Replication
In Xenopus early embryos, replication origins neither require specific DNA sequences nor is there an efficient S/M checkpoint, even though the whole genome (3 billion bases) is completely duplicated within 10–20 minutes. This leads to the “random-completion problem” of DNA replication in embryos, where one needs to find a mechanism that ensures complete, faithful, timely reproduction of the gen...
متن کاملPersistence length of chromatin determines origin spacing in Xenopus early-embryo DNA replication: quantitative comparisons between theory and experiment.
In Xenopus early embryos, replication origins neither require specific DNA sequences nor is there an efficient S/M checkpoint, even though the whole genome (3 billion bases) is completely duplicated within 10-20 minutes. This leads to the "random-completion problem" of DNA replication in embryos, where one needs to find a mechanism that ensures complete, faithful, timely reproduction of the gen...
متن کاملCell Timer/Cell Clock
Like the biological clock in the body, replication of each cell type (even different cells of the same organism) follows a timing program. Abnormal function of this timer could be an alarm for a disease like cancer. DNA replication starts from a specific point on the chromosome that is called the origin of replication. In contrast to prokaryotes in which DNA replication starts from a single ...
متن کاملIn vitro replication of recombinant plasmids carrying chromosomal segments of Xenopus laevis.
Recombinant plasmids carrying a segment of Xenopus laevis chromosomal DNA were constructed with plasmid pBR322 as the vector. A recombinant plasmid pXY65 carrying a 3.2-kilobase BamHI segment of the chromosome of X. laevis has been found to contain a repetitive sequence dispersed throughout the X. laevis chromosomes. This plasmid initiated replication in vitro when the supercoiled circular mole...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 98 9 شماره
صفحات -
تاریخ انتشار 2007