A correlation between a genetic defect in DNA repair and lack of hypermutation would be very significant, since there are no in vivo models to study mutation. Three knockout lines of mice have been obtained: PMS2 and MSH2 mismatch repair mice, and XPA nucleotide excision repair mice. Homozygous (-/-) knockout and littermate (+/+) mice are being immunized, and DNA will be prepared from B cells. Endogenous Vx and VH genes are being amplified by PCR, cloned, and sequenced. The frequency of mutation in the V and constant genes from knockout and control mice are compared. Preliminary results show different patterns of mutation in normal and mismatch repair deficient mice. Hybridoma cells were irradiated with ultraviolet light. The cells were then grown in vitro and harvested at different time points. DNA was prepared, and incubated with restriction enzymes and T4 endonuclease, which cleaves thymine dimers. Cleaved DNA was separated by gel electrophoresis, and different genes were identified by Southern blot analysis. Current results suggest that V genes have a slower rate of repair than the dihydrofolate reductase gene.
| Gearhart, Patricia J; Lindahl, Tomas; Neuberger, Michael S (2009) Preface. Philos Trans R Soc Lond B Biol Sci 364:561-2 |
| Saribasak, Huseyin; Rajagopal, Deepa; Maul, Robert W et al. (2009) Hijacked DNA repair proteins and unchained DNA polymerases. Philos Trans R Soc Lond B Biol Sci 364:605-11 |
| Martomo, Stella A; Saribasak, Huseyin; Yokoi, Masayuki et al. (2008) Reevaluation of the role of DNA polymerase theta in somatic hypermutation of immunoglobulin genes. DNA Repair (Amst) 7:1603-8 |
| Gearhart, Patricia J (2008) Response to ""Mutation frequency vs. mutation patterns: A comparison of the results in spleen and Peyer's patches"". DNA Repair (Amst) 7:1411-2 |
| Heltemes-Harris, Lynn M; Gearhart, Patricia J; Ghosh, Paritosh et al. (2008) Activation-induced deaminase-mediated class switch recombination is blocked by anti-IgM signaling in a phosphatidylinositol 3-kinase-dependent fashion. Mol Immunol 45:1799-806 |
| Alrefai, Rudaina H; Winter, David B; Bohr, Vilhelm A et al. (2007) Nucleotide excision repair in an immunoglobulin variable gene is less efficient than in a housekeeping gene. Mol Immunol 44:2800-5 |
| Martomo, Stella A; Gearhart, Patricia J (2006) Somatic hypermutation: subverted DNA repair. Curr Opin Immunol 18:243-8 |
| Martomo, Stella A; Yang, William W; Vaisman, Alexandra et al. (2006) Normal hypermutation in antibody genes from congenic mice defective for DNA polymerase iota. DNA Repair (Amst) 5:392-8 |
| Gearhart, Patricia J (2006) Antibody wars: extreme diversity. J Immunol 177:4235-6 |
| Wilson, Teresa M; Vaisman, Alexandra; Martomo, Stella A et al. (2005) MSH2-MSH6 stimulates DNA polymerase eta, suggesting a role for A:T mutations in antibody genes. J Exp Med 201:637-45 |
Showing the most recent 10 out of 32 publications
