Data from: The kinetochore prevents centromere-proximal crossover recombination during meiosis

During meiosis, crossover recombination is essential to link homologous
chromosomes and drive 22 faithful chromosome segregation. Crossover
recombination is non-random across the genome, 23 and centromere-proximal
crossovers are associated with an increased risk of aneuploidy, 24
including Trisomy 21 in humans. Here, we identify the conserved Ctf19/CCAN
kinetochore sub- 25 complex as a major factor that minimizes potentially
deleterious centromere-proximal crossovers 26 in budding yeast. We uncover
multi-layered suppression of pericentromeric recombination by the 27 Ctf19
complex, operating across distinct chromosomal distances. The Ctf19
complex prevents 28 meiotic DNA break formation, the initiating event of
recombination, proximal to the centromere. 29 The Ctf19 complex
independently drives the enrichment of cohesin throughout the broader 30
pericentromere to suppress crossovers, but not DNA breaks. This
non-canonical role of the 31 kinetochore in defining a chromosome domain
that is refractory to crossovers adds a new layer 32 of functionality by
which the kinetochore prevents the incidence of chromosome segregation 33
errors that generate aneuploid gametes.

在减数分裂过程中，交叉重组对于连接同源染色体并驱动忠实的染色体分离至关重要。交叉重组在基因组中呈非随机分布，且着丝粒近端的交叉与非整倍体（aneuploidy）风险增加相关，包括人类的21三体综合征（Trisomy21）。本文中，我们鉴定出保守的Ctf19/CCAN动粒（kinetochore）亚复合体是酿酒酵母（budding yeast）中减少潜在有害着丝粒近端交叉的主要因子。我们发现Ctf19复合体通过多层机制抑制着丝粒周围区域的重组，该抑制作用在不同染色体距离上均有体现。Ctf19复合体可阻止着丝粒近端减数分裂DNA断裂的形成——这是重组的起始事件。此外，Ctf19复合体独立驱动黏连蛋白（cohesin）在更广泛的着丝粒周围区域富集，以抑制交叉但不抑制DNA断裂。动粒这种定义对交叉具有抗性的染色体结构域的非经典功能，为其增添了新的功能层面，借此动粒可降低产生非整倍体配子（aneuploid gametes）的染色体分离错误发生率。