Fig. S5.

The 3′RR quasi-palindrome controls serum antibody production and antigen-specific immune response. (A) Serum Ig isotype levels quantified by ELISA in 8-wk-old wt and 3′PAL^Δ/Δ mice. Mean ± SEM are shown and significant differences indicated with a P value, according to the Student t test. (B) ELISA quantification of ovalbumin-specific Ig isotype in serum from immunized 8-wk-old wt^a/^b and 3′PAL^Δa/^wtb mice. Ab levels are indicated on the y axis in arbitrary units by comparison with a control serum. Days postimmunization are indicated on the x axis; arrows indicate first and second antigen injections. Each point is the mean of serum quantification for five animals. (Upper) “a” allotype responses for IgM, IgG1 and IgG2a isotypes; (Lower) “b” allotype responses for the same Ig classes. One significant experiment is shown.