What is break induced replication?
Break-induced replication (BIR) is a DNA double-strand break repair pathway that leads to genomic instabilities similar to those observed in cancer. BIR proceeds by a migrating bubble where asynchrony between leading and lagging strand synthesis leads to accumulation of long single-stranded DNA (ssDNA).
What is recombinational repair?
Recombination repair is a mechanism for generating a functional DNA molecule from two damaged molecules. It is an essential repair process for dividing cells because a replication fork may arrive at a damaged site, such as a thymine dimer, before the excision repair system has eliminated damage.
What is needed for homologous recombination?
Homologous recombination requires incoming DNA to be highly similar to the recipient genome, and so horizontal gene transfer is usually limited to similar bacteria.
What is homologous recombination and what is its outcome?
Homologous recombination (HR) is the genetic consequence of physical exchange between two aligned identical DNA regions on two separate chromosomes or on the same chromosome. HR mostly occurs between homologous chromosomes bearing distinct markers surrounding the exchange region.
What is a single ended double strand break?
Single-ended double-strand breaks (DSBs) are a common form of spontaneous DNA break, generated when the replisome encounters a discontinuity in the DNA template. Given their prevalence, understanding the mechanisms governing the fate(s) of single-ended DSBs is important.
How does homologous recombination work?
Homologous recombination is a type of genetic recombination that occurs during meiosis (the formation of egg and sperm cells). Paired chromosomes from the male and female parent align so that similar DNA sequences from the paired chromosomes cross over each other.
What are the steps of homologous recombination repair?
Homologous recombination can be divided into three key steps: strand exchange, branch migration and resolution.
How many double strand breaks a day?
The best known of such lesions is the DNA double-strand break (DSB). DNA DSBs occur in any given cell in the order of 10 to 50 per cell per day, depending on cell cycle and tissue (Vilenchik and Knudson, 2003).