Table 1.

Experimental design for mutation capture assay

Age group	Number of cohorts	Total replicates (mutation capture assays)	Total deletions detected	Average deletions per replicate
Day 4	3	11	101	9.20
Day 7	5	5	55	11.00
Day 10	3	12	156	13.00

We used at least three independent cohorts for each age group. Dependent on DNA yield, we then carried out between 1 and 4 repeat mutation capture assays per aging cohort. For one of the Day‐10 cohorts, we instead carried out a total of ten repeats of the mutation capture assay using a single tube of mtDNA extract from this single Day‐10 cohort. This was done to permit comparison of deletions detected repeatedly between cohorts and within a single cohort.