Minimal overlap between the OVA repertoires in adult, old, and MCMV+ mice. The degree of amino acid CDR3 sequence sharing between experimental groups (adult, old, MCMV) and within each group is shown. Unique clonotypes only appearing in one animal (regardless of group) were omitted for simplicity (see SI Appendix, Fig. S4 for a full list of CDR3 sequences). (A) Venn diagram showing shared clonotypes across experimental groups. Boxed numbers represent how many animals within that group contained that clonotype (i.e., sharing within the group). (B and C) The frequency of clonotypes within each mouse that are shared with an animal in either (B) the same or (C) any other experimental group. Comparisons between groups were by Kruskal–Wallis test, with Dunn correction for multiple pairwise comparisons. (D) The frequency of clonotypes within each mouse that are shared with an animal in the other experimental group shown. Comparisons between groups were by Mann–Whitney U test.