How do eukaryotic cells unpack and copy chromatin during chromosome replication?
Ever since Watson and Crick solved the double helical structure of DNA, it has been thought that the key to chromosome replication is the unwinding of the parental duplex, so that each strand can be used a template upon which to build another. But we now know that eukaryotic genomes are compacted many-fold by the assembly of chromatin, raising the question of how the eukaryotic chromosome replication machinery is able to unpack chromatin in order to allow the progression of DNA replication forks. Moreover, histone modifications across each chromosome control gene expression throughout the eukaryotic genome, and copying all these epigenetic modifications during chromosome replication is almost as important as duplicating the DNA itself. Nearly sixty years after Watson and Crick first proposed the basis of chromosome replication, we still know almost nothing about how the replication machinery is able to move through chromatin, and copy all the epigenetic modifications along the way. The
