Skip to main content
. Author manuscript; available in PMC: 2015 Jul 1.
Published in final edited form as: J Immunol. 2014 May 30;193(1):252–257. doi: 10.4049/jimmunol.1400433

FIGURE 2.

FIGURE 2

AID does not induce SHM in CH12 cells. (A) Mutation frequency of the Igh V region (VDJ). Unstimulated (U) IgA+ cells accumulated 1 mutation in 66,297 bases, and stimulated (S) IgA+ cells had 1 mutation in 68,593 bases. (B) Mutation frequency of Sμ–Sα junction. Unstimulated (U) IgA+ cells accumulated 2 mutations in 65,515 bases and 1 sequence with a deletion, and CIT-stimulated (S) IgA+ cells had 20 unique mutations in 64,568 bases and 17 sequences with a deletion. Data were obtained from two independent samples. p-values were calculated using z-test; p ≤ 0.05 was considered significant. (C) Diagram depicting the generation of deletions at the Sμ–Sα junction in CIT-stimulated IgA+ cells. DSBs generated in Sμ and Sα upon initial stimulation of an IgM+ CH12 cell are synapsed to form an initial Sμ–Sα junction. Stimulation of an IgA+ cell generates a new set of DSBs and results in the formation of a new Sμ–Sα junction, deleting the intervening switch sequence.