Fig 5. Comparison of Bmp2CreER activity levels and distribution assayed at E15.5 in LacZ-positive descendants, following tamoxifen (Tam) treatment between stages E11.25 to E11.75.

For each tamoxifen (Tam) treatment time, whole mount and adjacent longitudinal sections through dorsoventral axis of forelimb (FL) or hindlimb (HL) are oriented with distal at top, and anterior-to-posterior (digit 1–5) from left-to-right. Hatch marks in panels of longitudinal sections show the levels at which cross-sections through digit region were taken (rightmost panel sets; distal to proximal). Cross-sections are all oriented with dorsal at top and anterior-to-posterior (digit 1–5) from left-to-right. Note that Cre activity transitions from digit condensations and interdigital mesenchyme to primarily interdigits and collateral ligaments during this time window of tamoxifen administration.