Arnav Kishore
Research Mentor: Joann Sekiguchi
Mentor Department: Internal Medicine and Department of Human Genetics, Medicine
Author(s): Arnav Kishore, McKenna DeFoer, JoAnn Sekiguchi
Session: Session 3 (11:00 AM – 11:50 AM)
Presentation Type: Poster 89
Abstract
V(D)J recombination is a site-specific DNA rearrangement required for lymphocyte development and function. V(D)J recombination works by creating double-strand breaks (DSBs) between the variable, diversity, and joining segments of DNA, and then combining these segments to create V(D)J exons that code for the antigen-binding receptors found on these cells. The non-homologous end joining pathway (NHEJ) is used to repair these DSBs. The Artemis nuclease plays a vital role in nicking hairpin coding ends during recombination events. MRE11 is also a DNA nuclease and functions in the MRE11-RAD50-NBS1 (MRN) complex to repair DSBs in all major DNA DSB pathways. Previous research has shown that MRE11 might have a role in the repair of DSBs in V(D)J recombination. Mutations in Artemis or MRE11 can cause several medical disorders, featuring radiosensitivity, immune system defects, and genome instability. It is known that specific mutations in Artemis and MRE11 also cause aberrant V(D)J rearrangements, which suggests that they might function coordinately. We are investigating whether mice with hypomorphic mutations in both Artemis and MRE11 exhibit a different phenotype than those with only one mutation. Our research involves PCR amplification of DNA that may have undergone recombination, and using gel electrophoresis and Southern blots to determine our results from the gel and qualitatively analyze our product. Furthermore, we conduct qPCR, to quantitatively determine the level of recombination events. I hypothesize that the Artemis and MRE11 DNA nucleases work coordinately, and that the phenotype of the double-mutant mice will show a similar frequency of V(D)J recombination events as the single mutants.
