Substrains collected in Experiment 2.

Mice on a C57BL/6 background that were to be euthanized were obtained from two in-house SPF breeding units (laboratory code: Pan), resulting in a random selection of substrains. Substrain information is based on the information available from the breeding units. Due to the opportunistic design of the study, more detailed information on founder lines could not be obtained. The numbering in the left-hand column is used for identifying the substrains in the supporting materials (File S1).Substrains collected in Experiment 2.