School of Automation Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; School of Computer Science and Technology, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; MOE Key Lab for Intelligent Networks & Networks Security, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
School of Automation Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
Cell Genom. 2024 Aug 14;4(8):100626. doi: 10.1016/j.xgen.2024.100626. Epub 2024 Jul 30.
Understanding the roles played by centromeres in chromosome evolution and speciation is complicated by the fact that centromeres comprise large arrays of tandemly repeated satellite DNA, which hinders high-quality assembly. Here, we used long-read sequencing to generate nearly complete genome assemblies for four karyotypically diverse Papaver species, P. setigerum (2n = 44), P. somniferum (2n = 22), P. rhoeas (2n = 14), and P. bracteatum (2n = 14), collectively representing 45 gapless centromeres. We identified four centromere satellite (cenSat) families and experimentally validated two representatives. For the two allopolyploid genomes (P. somniferum and P. setigerum), we characterized the subgenomic distribution of each satellite and identified a "homogenizing" phase of centromere evolution in the aftermath of hybridization. An interspecies comparison of the peri-centromeric regions further revealed extensive centromere-mediated chromosome rearrangements. Taking these results together, we propose a model for studying cenSat competition after hybridization and shed further light on the complex role of the centromere in speciation.
理解着丝粒在染色体进化和物种形成中的作用很复杂，因为着丝粒包含大量串联重复的卫星 DNA，这阻碍了高质量的组装。在这里，我们使用长读测序技术为四个在染色体上具有多样性的罂粟属物种生成了几乎完整的基因组组装，分别是 P. setigerum（2n=44）、P. somniferum（2n=22）、P. rhoeas（2n=14）和 P. bracteatum（2n=14），总共代表了 45 个无间隙的着丝粒。我们鉴定了四个着丝粒卫星（cenSat）家族，并通过实验验证了其中两个家族的代表。对于两个异源多倍体基因组（P. somniferum 和 P. setigerum），我们描述了每个卫星的亚基因组分布，并鉴定了杂交后着丝粒进化的“同质化”阶段。对着丝粒周围区域的种间比较进一步揭示了广泛的着丝粒介导的染色体重排。综合这些结果，我们提出了一个研究杂交后 cenSat 竞争的模型，并进一步阐明了着丝粒在物种形成中的复杂作用。
