Genome-wide mapping of asynchronous replication in clonal mouse cells. Genome-wide mapping of asynchronous replication in clonal mouse cells

The entire genome is divided into distinct 1-2 Mb zones that replicate in an ordered and coordinated manner during S phase. While most regions of the genome replicate both alleles in a synchronous manner, some loci have been found to replicate asynchronously, with one allele undergoing DNA synthesis early in S phase, with the other replicating during late S. Random asynchronous replication timing is characterized by cell heterogeneity with some cells. having the maternal allele early replicating while in others, the orientation is reversed, with the paternal allele being early. This type of asynchronous replication can only be studied in a clonal or single cell manner. We have used the repli-seq method to study pre-B clonal f1 mouse cells in order to identify and study asynchronous regions in a genome-wide manner. Overall design: Examination of replication timing in mouse pre-b cells for four clonal CAST/C57BL F1 samples (e5, clone 8, clone 3, clone 2) and one clonal CAST sample. Three replicates were performed for each sample.全基因组被划分为独立的1~2 Mb区域，这些区域在细胞周期S期以有序且协同的方式完成复制。尽管基因组多数区域的两个等位基因会同步复制，但部分基因座已被发现存在异步复制现象：其中一个等位基因在S期早期完成DNA合成，另一个则在S期晚期进行复制。随机异步复制时序的典型特征为细胞异质性：部分细胞中母本等位基因复制更早，而其余细胞则呈现相反的复制取向，即父本等位基因复制更早。这类异步复制仅能通过克隆或单细胞层面的实验开展研究。本研究采用repli-seq技术，对前B细胞克隆型F1小鼠细胞进行分析，以在全基因组范围内鉴定并研究异步复制区域。实验设计概述：对5组小鼠前B细胞样本的复制时序进行检测，其中包括4组CAST/C57BL F1克隆样本（e5、克隆8、克隆3、克隆2）以及1组CAST克隆样本，每组样本均设置3次生物学重复。