a, Bone volume/total volume for femurs from 10-week-old
cathepsin K−/− mice (n = 3) after six
weeks parabiosis with cathepsin K+/− mice and from positive
(n = 4) and negative (n = 4) control
parabionts, analysed by von Kossa staining. b, Monocyte transfer.
Histograms represent percentage of tdTomato+ cells among bone
TRAP+ MGCs from
Csf1rCre;Rosa26LSL-YFP
recipients analysed by confocal microscopy (left) 11 days (n =
2) and 60 days (n = 5) after intravenous transfer at six weeks
of age of 3 × 106 Ly6C+ bone marrow cells from
Csf1rCre;Rosa26LSL-tdTomato
donors, and percentages of tdTomato+ cells among bone marrow
precursors and blood leukocytes, analysed by flow cytometry after 60 days
(n = 5, right). c, Representative high-power
confocal microscopy of the femur of a recipient mouse 60 days after intravenous
transfer (from b), stained with antibodies for tdTomato and YFP,
ELF97 phosphatase substrate and TOPRO-3. d, Representative
photographs of teeth (top) and CT scan of leg bones from
Csf1rcre;Csf1rfl/fl
mice (n = 3) transferred with monocytic cells from
Csf1rCre;Rosa26LSL-YFP
donors at P5, P8 and P11, and from wild-type and non-transferred
Csf1rcre;Csf1rfl/fl
controls. Arrows indicate the presence of teeth eruption (top panels) and bone
marrow cavity (bottom panels). e, Representative confocal
microscopy of a femur from mouse no. 3 in d, stained with YFP
antibody and with ELF97 and TOPRO-3. f, Number of TRAP+
osteoclasts in bone sections from mice in d and non-transferred
controls (left), and percentage of YFP+ TRAP+ cells in
transferred mice. The different symbols represent individual mice. Mean values
for three sections per mouse. At least 100 osteoclasts were quantified per
mouse. g, Percentages of YFP+ cells among bone marrow
precursors and blood leukocytes in the recipient mice (from d) at
the time of analysis. Data are mean ± s.d.; dots in graphs represent
individual mice; n indicates the number of mice per group;
ANOVA with Tukey’s multiple comparisons test. ***P
< 0.001 and ****P < 0.0001.