In eukaryotic cell,ORC1 accumulates in G1 and is degraded in S phase, but other ORC subunits remain at almost constant levels.

• 在真核细胞中ORC1亚基的量在细胞周期中呈现周期性波动(G1中期开始积累,S期开始减少),而ORC2-6在整个细胞周期保持稳定,这种ORC1的周期性波动被称为“ORC1周期”。