Centromere Sequence, Variation, and Function

项目摘要/摘要 染色体的准确分离确保了遗传信息的忠实遗传。中的缺陷 染色体分离会导致染色体数目的不平衡，或非整倍体，这是主要的 导致90%以上的人类癌症，并导致自然流产和出生缺陷(例如唐氏症) 综合症)。确保染色体在细胞分裂过程中均匀分离的基因是 着丝粒。着丝粒由重复的α卫星组成，每个卫星上有几个百万碱基 染色体。这些地区的重复性质给标准的短文阅读带来了巨大的挑战 测序和组装方法，结果是，所有着丝粒在人类基因组中仍然是未组装的。 着丝粒序列组装的缺乏极大地阻碍了我们对这些作用的理解 序列在维持基因组完整性所需的基本细胞生物学过程中发挥作用。这项提议旨在 要解决这一知识缺口，需要使用 长读测序技术和新的计算组装工具的结合。拟议中的工作 还将通过阐明着丝粒的遗传变异来重建着丝粒的进化史 在人类和类人猿身上。此外，这项工作将揭示着丝粒的遗传变异如何影响 通过对人类基因组中的全长着丝粒转录本进行测序和注释来绘制转录图景。 最后，这项提议将确定着丝粒的遗传变异是否会影响染色体形成的能力。 在细胞分裂过程中使用基于细胞的分析准确分离。总而言之，这项研究将揭示 人类着丝粒区域的线性组织并阐明这些区域的遗传变异 影响细胞分裂过程中染色体分离的准确性。

Project Summary/Abstract The accurate segregation of chromosomes ensures the faithful inheritance of genetic information. Defects in chromosome segregation can cause an imbalance in chromosome number, or aneuploidy, which is the leading cause of over 90% of human cancers and contributes to spontaneous abortion and birth defects (e.g. Down syndrome). The locus that ensures that chromosomes are equally segregated during cell division is the centromere. Centromeres are comprised of repetitive α-satellite that span several megabases on each chromosome. The repetitive nature of these regions has posed an enormous challenge to standard short-read sequencing and assembly methods, and as a result, all centromeres remain unassembled in the human genome. The lack of centromere sequence assemblies has greatly hindered our understanding of the role these sequences play in essential cell biological processes required to maintain genome integrity. This proposal aims to address this gap in knowledge by generating linear sequence assemblies of each human centromere using a combination of long-read sequencing technologies and novel computational assembly tools. The proposed work will also reconstruct the evolutionary history of centromeres by elucidating the genetic variation of centromeres in humans and apes. In addition, this work will uncover how genetic variation at centromeres impacts the transcriptional landscape by sequencing and annotating full-length centromeric transcripts in the human genome. Finally, this proposal will determine if genetic variation at centromeres impacts the ability of chromosomes to be accurately segregated during cell division using cell-based assays. Taken together, this research will uncover the linear organization of human centromeric regions and elucidate how genetic variation in these regions impacts the accuracy of chromosome segregation during cell division.