Table 1.

Number and distribution of BrdU label-retaining cells in tail hair follicles (HF) of wild-type mice after a 70 day chase period

Number of BrdU-labelled cells±s.d. (range)
Sebaceous gland (SG) HF infundibulum Non-cycling region of HF beneath SG Cycling region of HF
Heavy BrdULight BrdUHeavy BrdULight BrdUHeavy BrdULight BrdUHeavy BrdULight BrdU
Outer follicles (n=20)0.3±0.6 (0-2)0.6±0.8 (0-2)0.2±0.4 (0-1)1.1±1.0 (0-3)46.9±19.1 (21-79)35.3±12.7 (15-65)0.7±1.0 (0-3)14.3±11.7 (0-43)
Central follicles (n=10)0.4±0.7 (0-2)0.5±0.5 (0-1)0.0±0.0 (0-0)1.0±1.2 (0-4)15.3±4.7 (10-23)12.6±5.7 (4-21)0.1±0.3 (0-1)2.0±2.1 (0-7)
  • The number of BrdU-labelled cells was determined by microscopic examination of formaldehyde-fixed tail epidermal wholemounts prepared from three wild-type mice. Wholemounts were stained by double-label immunofluorescence to detect BrdU and keratin 14. Cells with the most intense BrdU labelling were counted as `heavy BrdU' (Fig. 1G). BrdU-labelled cells that were estimated to have less than 50% of the maximum labelling observed for any cell in that follicle were classified as `light BrdU' (Fig. 1G); these cells are likely to have undergone at least two cell divisions since incorporating the BrdU label.