Fig. 8. Contribution to HH-responding bladder and external genitalia mesenchymes
from the PCM. Above is a schematic depicting the inducible
Gli1-CreERT2 allele and the experimental timecourse employed to
labeling HH-responsive tissues. (A-D,F,G) LacZ staining
of urogenital tissues in Gli1-CreERT2;R26R embryos that
were administered tamoxifen at E8.75
9.0. (A,C) Whole-mount view of
stained embryos at E10.5 and E13.5. (B,D) Mid-sagittal sections show the
contribution of HH-responsive cells initially to the PCM (yellow box and
inset) and to the mesenchyme of the GT and bladder (D, red arrow). (E)
Diagram of newborn sagittal specimens; yellow boxes indicate likely primordia
of penile bone and corporal bodies and the bladder, labeled and shown in F and
G, respectively. b, bladder; c, cloaca; gt, genital tubercle; hg, hindgut;
pcm, peri-cloacal mesenchyme; r, rectum; t, tail bud.