1. Illustration of UniFrac calculations for a pair of young participants and a pair of elderly participants at baseline.
Illustration of UniFrac calculations for a pair of young participants and a pair of elderly participants at baseline. Six sequences with V-segment IGHV3-11, J-segment IGHJ4, and a CDR3 length of 45 nucleotides were sampled from each participant. Unshared branches are highlighted in bold. [Tree plots were generated using the R package “ggtree” (50)]. (A) Participants YN2 and YN3. The unshared branch length is 18.66, and the total branch length After applying the weighting scheme described in SI Materials and Methods, the weighted unshared branch length is 3.17 and the weighted total branch length is 3.75, giving a UniFrac value of (B) Participants EP4 and EN5. The unshared branch length is 21.95, the total branch length is 22.43, the weighted unshared branch length is 4.37, the weighted total branch length is 4.88, and the UniFrac value is Notice how the elderly pair’s UniFrac value turns out larger than the young pair’s due to an increased prevalence of highly mutated sequences in unshared clades.
Charles F. A. de Bourcy et al. PNAS 2017;114:5:
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