Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Curr Biol. 2021 Jan 11;31(1):66-76.e6. doi: 10.1016/j.cub.2020.09.077. Epub 2020 Oct 29.
DNA replication is a ubiquitous and conserved cellular process. However, regulation of DNA replication is only understood in a small fraction of organisms that poorly represent the diversity of genetic systems in nature. Here we used computational and experimental approaches to examine the function and evolution of one such system, the replication band (RB) in spirotrich ciliates, which is a localized, motile hub that traverses the macronucleus while replicating DNA. We show that the RB can take unique forms in different species, from polar bands to a "replication envelope," where replication initiates at the nuclear periphery before advancing inward. Furthermore, we identify genes involved in cellular transport, including calcium transporters and cytoskeletal regulators, that are associated with the RB and may be involved in its function and translocation. These findings highlight the evolution and diversity of DNA replication systems and provide insights into the regulation of nuclear organization and processes.
DNA 复制是一种普遍存在且保守的细胞过程。然而，DNA 复制的调控仅在一小部分生物体中得到理解，这些生物体在很大程度上不能代表自然界中遗传系统的多样性。在这里，我们使用计算和实验方法来研究复制带（RB）在旋毛类纤毛虫中的功能和进化，该复制带是一种定位于动粒的、运动的中心，在复制 DNA 的同时穿越着巨核。我们表明，RB 在不同物种中可以呈现独特的形式，从极性带到“复制包络”，其中复制在向核内推进之前，起始于核周。此外，我们鉴定了与 RB 相关的参与细胞运输的基因，包括钙转运体和细胞骨架调节剂，这些基因可能参与其功能和易位。这些发现突出了 DNA 复制系统的进化和多样性，并为核组织和过程的调控提供了新的见解。
