Mice were sacrificed at 4 weeks post-infection and we examined the numbers of B. burgdorferi in heart and bladder tissue by qPCR by measuring copies of B. burgdorferi recA (data not shown) and ospA (Figure 7) relative to mouse nidogen. Despite the immaturity of the immune system at the time of infection, the infection of mice with B. burgdorferi at a young age did not affect the bacterial burden in these mice when sampled at 3–4 weeks of age compared to mice infected as adults in previous studies (data not shown) [15]. Here, RAD51 is linked to infection.