DNA Replication and Genome Instability
The Barlow lab studies how DNA replication is controlled, and mis-regulation leads to genome instability.
Accurate cell division requires the faithful and complete duplication of nuclear DNA, providing the daughter cell a precise copy of the encoded genomic information. For faithful and complete replication, the replication phases of initiation, elongation and termination must be coordinated to copy the nuclear DNA once and only once per cell cycle. The Barlow lab uses a combination of molecular biology, microscopy, and genome-wide sequencing techniques to investigate the molecular and genetic factors that predispose replicating cells to DNA damage and genome instability.
Using the mouse immune system as our model, we investigate how complex chromosome rearrangements are formed in otherwise healthy cells, triggering the earliest events in tumorigenesis. Activated B lymphocytes can have a doubling time as short as 8 hours, suggesting that these rapidly proliferating cells are particularly vulnerable to replicative stress, and may contribute to lymphomagenesis. Programmed chromosome rearrangement formation is essential for antibody formation during V(D)J recombination and affinity maturation during class switch recombination (CSR). Both VDJ recombination and CSR are important for a robust adaptive immune system response. Higher levels of aberrant chromosome rearrangements increase the chance to develop cancer and may lead to defects in adaptive immunity. Secondary structures that form in DNA are potent sources of replication stress and help guide “targeted” DNA damage for antibody formation. We are investigating the role of two types of secondary structures—R-loops and G quadruplexes—on genome stability during replication and antibody affinity maturation.
We also investigate the role defective R-loop removal on generating genome instability using mice and human cells lacking the RNA:DNA helicase Senataxin. Loss of Senataxin leads to a rare, autosomal recessive neurodegenerative condition called Ataxia with Oculomotor Apraxia type 2 (AOA2).
Accurate cell division requires the faithful and complete duplication of nuclear DNA, providing the daughter cell a precise copy of the encoded genomic information. For faithful and complete replication, the replication phases of initiation, elongation and termination must be coordinated to copy the nuclear DNA once and only once per cell cycle. The Barlow lab uses a combination of molecular biology, microscopy, and genome-wide sequencing techniques to investigate the molecular and genetic factors that predispose replicating cells to DNA damage and genome instability.
Using the mouse immune system as our model, we investigate how complex chromosome rearrangements are formed in otherwise healthy cells, triggering the earliest events in tumorigenesis. Activated B lymphocytes can have a doubling time as short as 8 hours, suggesting that these rapidly proliferating cells are particularly vulnerable to replicative stress, and may contribute to lymphomagenesis. Programmed chromosome rearrangement formation is essential for antibody formation during V(D)J recombination and affinity maturation during class switch recombination (CSR). Both VDJ recombination and CSR are important for a robust adaptive immune system response. Higher levels of aberrant chromosome rearrangements increase the chance to develop cancer and may lead to defects in adaptive immunity. Secondary structures that form in DNA are potent sources of replication stress and help guide “targeted” DNA damage for antibody formation. We are investigating the role of two types of secondary structures—R-loops and G quadruplexes—on genome stability during replication and antibody affinity maturation.
We also investigate the role defective R-loop removal on generating genome instability using mice and human cells lacking the RNA:DNA helicase Senataxin. Loss of Senataxin leads to a rare, autosomal recessive neurodegenerative condition called Ataxia with Oculomotor Apraxia type 2 (AOA2).
