The DNA replication checkpoint maintains expression homeostasis during replication stress. Saccharomyces cerevisiae S288C

DNA replication proceeds in a well-defined temporal ordered, with some chromosomal domains replicated early in S phase, while others replicating at late S. The sequential pattern introduces a transient imbalance in gene dosages: copy number of genes that replicate early increases before that of later replicated one. In bacteria, replication-dependent dosage imbalance propagates to modulate gene expression, increasing the in the expression of early replicating genes relative to late replicating ones. This, in fact, provides bacteria with the ability to regulate gene expression in a growth-dependent manner; In multiple bacteria, for example, growth-related genes are positioned close to the replication origin, leading to their increased expression in rapidly growing cells. Similarly, in certain bacteria DNA-damage repair genes are also positioned close to the replication origin, resulting in increased expression of these genes under conditions of replication stress that slows down replication.