DNA polymerase theta has been implicated in the process of somatic hypermutation in immunoglobulin variable genes based on several reports of alterations in the frequency and spectra of mutations from Polq-/- mice. However, these studies have contrasting results on mutation frequencies and the types of nucleotide substitutions, which question the role of polymerase theta in hypermutation. DNA polymerase eta has a dominant effect on mutation and may substitute in the absence of polymerase theta to affect the pattern. Therefore, we have examined mutation in mice deficient for both polymerases eta and theta. The mutation frequencies in rearranged variable genes from Peyers patches were similar in wild type, Polq-/-, Polh-/-, and Polq-/-Polh-/- mice. The types of substitutions were also similar between wild type and Polq-/- clones, and between Polh-/- and Polq-/-Polh-/- clones. Furthermore, there was no difference in heavy chain class switching in splenic B cells from the four groups of mice. These results indicate that polymerase theta does not play a significant role in the generation of somatic mutation in immunoglobulin genes.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Intramural Research (Z01)
Project #
1Z01AG000732-13
Application #
7732301
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
13
Fiscal Year
2008
Total Cost
$205,054
Indirect Cost
Name
National Institute on Aging
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Gearhart, Patricia J; Lindahl, Tomas; Neuberger, Michael S (2009) Preface. Philos Trans R Soc Lond B Biol Sci 364:561-2
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