PEC and splenic B1 cell derived IgA VH sequences display high frequencies of nucleotide exchanges due to somatic hypermutation.

<p>Frequency of mutations observed in the IgM or IgA VH region sequences derived from PEC and splenic B1 cells cultured for 4 days with the indicated combinations of IgA CSR inducing factors. (A) Each colored sector represents a particular number of mutations found at a particular frequency. Total number of sequences is shown in the middle. (B) Number of replacement and silent mutations amongst IgM and IgA VH sequences derived from indicated B cell populations. Sequences were analyzed using SEQUENCHER™ Version 4.1 for Macintosh software (Gene Codes Corporation). Assignment of VH chain was done using VBASE2 database (<a href="http://www.vbase2.org/" target="_blank">http://www.vbase2.org/</a>). Only functional sequences were included for the mutation analysis. Bars represent mean ± SD.