Single molecule analysis of Human DNA replication

所有的细胞都包含一个完整的生物体DNA拷贝，这是生命的遗传蓝图，被包装成称为染色体的离散单元。由于新细胞需要遗传物质的拷贝，因此在细胞分裂之前，染色体必须完全准确地复制。这需要DNA复制过程从染色体上的数千个位点开始-称为DNA复制起始位点。我们的项目旨在确定人类细胞中复制起始位点的位置。这一点很重要，因为复制起始位点的位置和分布与癌症等人类疾病的发生有关。由于细胞之间存在很大的变异性，因此识别人类细胞中的DNA复制起始位点一直是一个挑战。到目前为止，大多数实验都使用了数百万个细胞的平均值，但这隐藏了细胞之间的变异性。我们开发了一种新技术，可以识别数千个单个分子上的DNA复制起始位点，每个分子都起源于单个细胞。我们的方法还可以识别难以复制的特定序列。这将使我们能够检验这样一个假设，即一些被认为参与复制起始的位点实际上是阻碍DNA复制的位点。区分启动和阻碍DNA复制的位点对于理解某些人类疾病的遗传不稳定性的原因至关重要。

All cells contain a complete copy of the organism's DNA, the genetic blueprint of life, packaged into discrete units called chromosomes. Since new cells need a copy of the genetic material, the chromosomes must be completely and accurately replicated before the cell can divide. This requires the process of DNA replication to start at thousands of sites across the chromosomes - called DNA replication initiation sites. Our project aims to determine the location of replication initiation sites in human cells. This is important because the location and distribution of replication initiation sites have been implicated in causing human diseases such as cancer.It has been challenging to identify DNA replication initiation sites in human cells, because there is a lot of variability between cells. To date, most experiments have used the average from millions of cells, but this hides the variability between cells. We have developed a novel technology that identifies DNA replication initiation sites on thousands of single molecules that each originated in a single cell. Our approach can also identify specific sequences that are challenging to copy. This will allow us to test the hypothesis that some sites, thought to be involved in replication initiation, in fact are sites that impede DNA replication. Distinguishing between sites that initiate versus impede DNA replication will be crucial in understanding the causes of genetic instability that underlie some human diseases.