Break-induced replication (BIR) is a pathway specialized in repair of double-strand DNA breaks with only one end capable of invading homologous template that can arise following replication collapse, telomere erosion or DNA cutting by site-specific endonucleases. For a long time, yeast remained the only model system to study BIR. Studies in yeast demonstrated that BIR represents an unusual mode of DNA synthesis that is driven by a migrating bubble and leads to conservative inheritance of newly synthesized DNA. This unusual type of DNA synthesis leads to high levels of mutations and chromosome rearrangements. Recently, multiple examples of BIR were uncovered in mammalian cells that allowed the comparison of BIR between organisms. It appeared initially that BIR in mammalian cells is predominantly independent of RAD51, and therefore different from BIR that is predominantly Rad51-dependent in yeast. However, a series of systematic studies utilizing site-specific DNA breaks for BIR initiation in mammalian reporters led to the discovery of highly efficient RAD51-dependent BIR, allowing side-by side comparison with BIR in yeast which is the focus of this review.

断裂诱导复制 (BIR) 是一种专门修复双链 DNA 断裂的途径，只有一端能够侵入同源模板，这种断裂可能在复制崩溃、端粒侵蚀或位点特异性核酸内切酶切割 DNA 后出现。长期以来，酵母仍然是研究 BIR 的唯一模型系统。对酵母的研究表明，BIR 代表了一种不寻常的 DNA 合成模式，这种模式由迁移气泡驱动，并导致新合成 DNA 的保守遗传。这种不寻常的 DNA 合成类型会导致高水平的突变和染色体重排。最近，在哺乳动物细胞中发现了多个 BIR 实例，从而可以比较生物体之间的 BIR。最初看来哺乳动物细胞中的 BIR 主要独立于 RAD51，因此不同于在酵母中主要依赖于 Rad51 的 BIR。然而，一系列利用位点特异性 DNA 断裂在哺乳动物报告基因中启动 BIR 的系统研究导致发现了高效的 RAD51 依赖性 BIR，允许与酵母中的 BIR 进行并排比较，这是本综述的重点。