Analysis of human chromosome 13q neocentromere formation

描述（由申请方提供）：本提案的总体目标是表征人类着丝粒的结构和功能，着丝粒是确保细胞分裂期间染色体正确分离的基本染色体组分。 染色体分离错误导致非整倍体、出生缺陷和肿瘤。新着丝粒是临床上确定的人类着丝粒变体，其为从内源性着丝粒分离的染色体片段提供有丝分裂稳定性。它们在单拷贝或低拷贝基因组DNA上形成，并且不包含在所有内源性人类着丝粒中发现的串联重复的α卫星DNA。新着丝粒在复杂的低拷贝基因组DNA上的形成允许将人类着丝粒的结构和功能解剖到潜在的线性DNA序列上。以下三个特定目的将通过以下方式研究人类着丝粒：1）鉴定在染色体13 q中形成的12个新着丝粒集合中发现的DNA序列，2）使用新着丝粒研究染色质结构域结构和人类着丝粒功能所需的最小DNA序列，3）分析来自相同染色体位置的多个独立新着丝粒处的DNA序列和染色体背景，以研究人着丝粒形成的要求。对人类着丝粒结构、功能和形成的研究将极大地促进人类人工染色体的构建，并将其用作自主基因表达载体。

DESCRIPTION (provided by applicant): The overall objective of this proposal is to characterize the structure and function of human centromeres, which are the fundamental chromosome components that ensure proper chromosome segregation during cell division. Errors in chromosome segregation result in aneuploidy and birth defects, and neoplasias. Neocentromeres are a clinically ascertained human centromere variant that provide mitotic stability to chromosomal fragments that have separated from endogenous centromeres. They have formed on single or low copy genomic DNA and do not contain the tandemly repeated alpha satellite DNA found at all endogenous human centromeres. The formation of neocentromeres on complex low-copy genomic DNA permits the structural and functional dissection of human centromeres onto the underlying linear DNA sequences. The following three Specific Aims will investigate human centromeres by 1) identification of the DNA sequences found at a collection of 12 neocentromeres that have formed in chromosome 13q, 2) use of neocentromeres to investigate the chromatin domain structure and minimal DNA sequences required for human centromere function, 3) analysis of the DNA sequence and chromosomal context at multiple independent neocentromeres from the same chromosomal location to investigate the requirements for human centromere formation. Investigation of human centromere structure, function and formation will greatly facilitate the construction of artificial human chromosomes for use as autonomous gene expression vectors.