Extended Data Figure 2. BrdU pulse labelling of human LECs.

a, Whole mount of a human lens capsule showing BrdU⁺ cells (brown) by enzymatic immunohistology and diaminobenzidine staining. b, High-magnification images of human donor lenses showing BrdU⁺ LECs. c, Bar graph showing quantification of BrdU⁺ cells. There was an age-dependent decrease in the number of BrdU⁺ cells (8 months, 39.9 ± 8.1; 30 years, 20.3 ± 7.3 and 40 years, 5.9 ± 2.9; 8 months versus 40 years, *P < 0.05). Six randomly chosen fields of each capsule were used for analysis, four samples in each group, (n = 24 fields, chosen over four samples). d, High-magnification images of whole-mount staining of human lens capsules with or without injury showed a marked increase in the number of BrdU⁺ cells after injury. e, Bar graph showing quantification of BrdU⁺ cells. The contralateral eyes from the respective donors were used as controls. There was a significant increase in number of BrdU⁺ cells. No injury, 1.5 ± 1.2; after injury, 18.4 ± 4.2; fold change after injury, 11.3 ± 2.5; *P < 0.05. Six randomly chosen fields within the germinative zone of each capsule were used for analysis, five samples in each group (n = 30 fields, chosen over five samples). Data shown as means ± s.d. f, Cultured human fetal LECs were positive for BMI-1 (green, right upper panel); co-staining of PAX6 (red) and Ki67 (green), middle panels; co-staining of SOX2 (red) and Ki67 (green), lower panels. g, Co-staining of PAX6 (red) and SOX2 (green) of human fetal LECs. All scale bars, 100 μm.